diff --git a/src/client/app/ch/tags/channel.tag b/src/client/app/ch/tags/channel.tag
index 1ebc3cceb..4856728de 100644
--- a/src/client/app/ch/tags/channel.tag
+++ b/src/client/app/ch/tags/channel.tag
@@ -165,7 +165,7 @@
 <mk-channel-post>
 	<header>
 		<a class="index" @click="reply">{ post.index }:</a>
-		<a class="name" href={ _URL_ + '/@' + acct }><b>{ post.user.name }</b></a>
+		<a class="name" href={ _URL_ + '/@' + acct }><b>{ getUserName(post.user) }</b></a>
 		<mk-time time={ post.createdAt }/>
 		<mk-time time={ post.createdAt } mode="detail"/>
 		<span>ID:<i>{ acct }</i></span>
@@ -230,10 +230,12 @@
 	</style>
 	<script lang="typescript">
 		import getAcct from '../../../../acct/render';
+		import getUserName from '../../../../renderers/get-user-name';
 
 		this.post = this.opts.post;
 		this.form = this.opts.form;
 		this.acct = getAcct(this.post.user);
+		this.name = getUserName(this.post.user);
 
 		this.reply = () => {
 			this.form.update({
@@ -244,7 +246,7 @@
 </mk-channel-post>
 
 <mk-channel-form>
-	<p v-if="reply"><b>&gt;&gt;{ reply.index }</b> ({ reply.user.name }): <a @click="clearReply">[x]</a></p>
+	<p v-if="reply"><b>&gt;&gt;{ reply.index }</b> ({ getUserName(reply.user) }): <a @click="clearReply">[x]</a></p>
 	<textarea ref="text" disabled={ wait } oninput={ update } onkeydown={ onkeydown } onpaste={ onpaste } placeholder="%i18n:ch.tags.mk-channel-form.textarea%"></textarea>
 	<div class="actions">
 		<button @click="selectFile">%fa:upload%%i18n:ch.tags.mk-channel-form.upload%</button>
@@ -286,6 +288,8 @@
 
 	</style>
 	<script lang="typescript">
+		import getUserName from '../../../../renderers/get-user-name';
+
 		this.mixin('api');
 
 		this.channel = this.opts.channel;
@@ -373,6 +377,8 @@
 				}
 			});
 		};
+
+		this.getUserName = getUserName;
 	</script>
 </mk-channel-form>
 
diff --git a/src/client/app/common/scripts/compose-notification.ts b/src/client/app/common/scripts/compose-notification.ts
index ebc15952f..e99d50296 100644
--- a/src/client/app/common/scripts/compose-notification.ts
+++ b/src/client/app/common/scripts/compose-notification.ts
@@ -1,5 +1,6 @@
 import getPostSummary from '../../../../renderers/get-post-summary';
 import getReactionEmoji from '../../../../renderers/get-reaction-emoji';
+import getUserName from '../../../../renderers/get-user-name';
 
 type Notification = {
 	title: string;
@@ -21,35 +22,35 @@ export default function(type, data): Notification {
 
 		case 'mention':
 			return {
-				title: `${data.user.name}さんから:`,
+				title: `${getUserName(data.user)}さんから:`,
 				body: getPostSummary(data),
 				icon: data.user.avatarUrl + '?thumbnail&size=64'
 			};
 
 		case 'reply':
 			return {
-				title: `${data.user.name}さんから返信:`,
+				title: `${getUserName(data.user)}さんから返信:`,
 				body: getPostSummary(data),
 				icon: data.user.avatarUrl + '?thumbnail&size=64'
 			};
 
 		case 'quote':
 			return {
-				title: `${data.user.name}さんが引用:`,
+				title: `${getUserName(data.user)}さんが引用:`,
 				body: getPostSummary(data),
 				icon: data.user.avatarUrl + '?thumbnail&size=64'
 			};
 
 		case 'reaction':
 			return {
-				title: `${data.user.name}: ${getReactionEmoji(data.reaction)}:`,
+				title: `${getUserName(data.user)}: ${getReactionEmoji(data.reaction)}:`,
 				body: getPostSummary(data.post),
 				icon: data.user.avatarUrl + '?thumbnail&size=64'
 			};
 
 		case 'unread_messaging_message':
 			return {
-				title: `${data.user.name}さんからメッセージ:`,
+				title: `${getUserName(data.user)}さんからメッセージ:`,
 				body: data.text, // TODO: getMessagingMessageSummary(data),
 				icon: data.user.avatarUrl + '?thumbnail&size=64'
 			};
@@ -57,7 +58,7 @@ export default function(type, data): Notification {
 		case 'othello_invited':
 			return {
 				title: '対局への招待があります',
-				body: `${data.parent.name}さんから`,
+				body: `${getUserName(data.parent)}さんから`,
 				icon: data.parent.avatarUrl + '?thumbnail&size=64'
 			};
 
diff --git a/src/client/app/common/views/components/autocomplete.vue b/src/client/app/common/views/components/autocomplete.vue
index 38eaf8650..8837fde6b 100644
--- a/src/client/app/common/views/components/autocomplete.vue
+++ b/src/client/app/common/views/components/autocomplete.vue
@@ -3,7 +3,7 @@
 	<ol class="users" ref="suggests" v-if="users.length > 0">
 		<li v-for="user in users" @click="complete(type, user)" @keydown="onKeydown" tabindex="-1">
 			<img class="avatar" :src="`${user.avatarUrl}?thumbnail&size=32`" alt=""/>
-			<span class="name">{{ user.name }}</span>
+			<span class="name">{{ getUserName(user) }}</span>
 			<span class="username">@{{ getAcct(user) }}</span>
 		</li>
 	</ol>
@@ -22,6 +22,7 @@ import Vue from 'vue';
 import * as emojilib from 'emojilib';
 import contains from '../../../common/scripts/contains';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 const lib = Object.entries(emojilib.lib).filter((x: any) => {
 	return x[1].category != 'flags';
@@ -107,6 +108,7 @@ export default Vue.extend({
 	},
 	methods: {
 		getAcct,
+		getUserName,
 		exec() {
 			this.select = -1;
 			if (this.$refs.suggests) {
diff --git a/src/client/app/common/views/components/messaging.vue b/src/client/app/common/views/components/messaging.vue
index 4ab3e46e8..9b1449daa 100644
--- a/src/client/app/common/views/components/messaging.vue
+++ b/src/client/app/common/views/components/messaging.vue
@@ -14,7 +14,7 @@
 					tabindex="-1"
 				>
 					<img class="avatar" :src="`${user.avatarUrl}?thumbnail&size=32`" alt=""/>
-					<span class="name">{{ user.name }}</span>
+					<span class="name">{{ getUserName(user) }}</span>
 					<span class="username">@{{ getAcct(user) }}</span>
 				</li>
 			</ol>
@@ -33,7 +33,7 @@
 				<div>
 					<img class="avatar" :src="`${isMe(message) ? message.recipient.avatarUrl : message.user.avatarUrl}?thumbnail&size=64`" alt=""/>
 					<header>
-						<span class="name">{{ isMe(message) ? message.recipient.name : message.user.name }}</span>
+						<span class="name">{{ getUserName(isMe(message) ? message.recipient : message.user) }}</span>
 						<span class="username">@{{ getAcct(isMe(message) ? message.recipient : message.user) }}</span>
 						<mk-time :time="message.createdAt"/>
 					</header>
@@ -52,6 +52,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: {
@@ -94,6 +95,7 @@ export default Vue.extend({
 	},
 	methods: {
 		getAcct,
+		getUserName,
 		isMe(message) {
 			return message.userId == (this as any).os.i.id;
 		},
diff --git a/src/client/app/common/views/components/welcome-timeline.vue b/src/client/app/common/views/components/welcome-timeline.vue
index ef0c7beaa..bfb4b2bbe 100644
--- a/src/client/app/common/views/components/welcome-timeline.vue
+++ b/src/client/app/common/views/components/welcome-timeline.vue
@@ -6,7 +6,7 @@
 		</router-link>
 		<div class="body">
 			<header>
-				<router-link class="name" :to="`/@${getAcct(post.user)}`" v-user-preview="post.user.id">{{ post.user.name }}</router-link>
+				<router-link class="name" :to="`/@${getAcct(post.user)}`" v-user-preview="post.user.id">{{ getUserName(post.user) }}</router-link>
 				<span class="username">@{{ getAcct(post.user) }}</span>
 				<div class="info">
 					<router-link class="created-at" :to="`/@${getAcct(post.user)}/${post.id}`">
@@ -25,6 +25,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	data() {
@@ -38,6 +39,7 @@ export default Vue.extend({
 	},
 	methods: {
 		getAcct,
+		getUserName,
 		fetch(cb?) {
 			this.fetching = true;
 			(this as any).api('posts', {
diff --git a/src/client/app/desktop/views/components/followers-window.vue b/src/client/app/desktop/views/components/followers-window.vue
index 623971fa3..d37ca745a 100644
--- a/src/client/app/desktop/views/components/followers-window.vue
+++ b/src/client/app/desktop/views/components/followers-window.vue
@@ -1,7 +1,7 @@
 <template>
 <mk-window width="400px" height="550px" @closed="$destroy">
 	<span slot="header" :class="$style.header">
-		<img :src="`${user.avatarUrl}?thumbnail&size=64`" alt=""/>{{ user.name }}のフォロワー
+		<img :src="`${user.avatarUrl}?thumbnail&size=64`" alt=""/>{{ name }}のフォロワー
 	</span>
 	<mk-followers :user="user"/>
 </mk-window>
@@ -9,8 +9,15 @@
 
 <script lang="ts">
 import Vue from 'vue';
+import getUserName from '../../../../../renderers/get-user-name';
+
 export default Vue.extend({
-	props: ['user']
+	props: ['user'],
+	computed {
+		name() {
+			return getUserName(this.user);
+		}
+	}
 });
 </script>
 
diff --git a/src/client/app/desktop/views/components/following-window.vue b/src/client/app/desktop/views/components/following-window.vue
index 612847b38..cbd8ec5f9 100644
--- a/src/client/app/desktop/views/components/following-window.vue
+++ b/src/client/app/desktop/views/components/following-window.vue
@@ -1,7 +1,7 @@
 <template>
 <mk-window width="400px" height="550px" @closed="$destroy">
 	<span slot="header" :class="$style.header">
-		<img :src="`${user.avatarUrl}?thumbnail&size=64`" alt=""/>{{ user.name }}のフォロー
+		<img :src="`${user.avatarUrl}?thumbnail&size=64`" alt=""/>{{ name }}のフォロー
 	</span>
 	<mk-following :user="user"/>
 </mk-window>
@@ -9,8 +9,15 @@
 
 <script lang="ts">
 import Vue from 'vue';
+import getUserName from '../../../../../renderers/get-user-name';
+
 export default Vue.extend({
-	props: ['user']
+	props: ['user'],
+	computed: {
+		name() {
+			return getUserName(this.user);
+		}
+	}
 });
 </script>
 
diff --git a/src/client/app/desktop/views/components/friends-maker.vue b/src/client/app/desktop/views/components/friends-maker.vue
index 351e9e1c5..acc4542d9 100644
--- a/src/client/app/desktop/views/components/friends-maker.vue
+++ b/src/client/app/desktop/views/components/friends-maker.vue
@@ -7,7 +7,7 @@
 				<img class="avatar" :src="`${user.avatarUrl}?thumbnail&size=42`" alt="" v-user-preview="user.id"/>
 			</router-link>
 			<div class="body">
-				<router-link class="name" :to="`/@${getAcct(user)}`" v-user-preview="user.id">{{ user.name }}</router-link>
+				<router-link class="name" :to="`/@${getAcct(user)}`" v-user-preview="user.id">{{ getUserName(user) }}</router-link>
 				<p class="username">@{{ getAcct(user) }}</p>
 			</div>
 			<mk-follow-button :user="user"/>
@@ -23,6 +23,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	data() {
@@ -38,6 +39,7 @@ export default Vue.extend({
 	},
 	methods: {
 		getAcct,
+		getUserName,
 		fetch() {
 			this.fetching = true;
 			this.users = [];
diff --git a/src/client/app/desktop/views/components/messaging-room-window.vue b/src/client/app/desktop/views/components/messaging-room-window.vue
index f29f9b74e..7f8c35c2f 100644
--- a/src/client/app/desktop/views/components/messaging-room-window.vue
+++ b/src/client/app/desktop/views/components/messaging-room-window.vue
@@ -1,6 +1,6 @@
 <template>
 <mk-window ref="window" width="500px" height="560px" :popout-url="popout" @closed="$destroy">
-	<span slot="header" :class="$style.header">%fa:comments%メッセージ: {{ user.name }}</span>
+	<span slot="header" :class="$style.header">%fa:comments%メッセージ: {{ name }}</span>
 	<mk-messaging-room :user="user" :class="$style.content"/>
 </mk-window>
 </template>
@@ -9,10 +9,14 @@
 import Vue from 'vue';
 import { url } from '../../../config';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['user'],
 	computed: {
+		name(): string {
+			return getUserName(this.user);
+		},
 		popout(): string {
 			return `${url}/i/messaging/${getAcct(this.user)}`;
 		}
diff --git a/src/client/app/desktop/views/components/notifications.vue b/src/client/app/desktop/views/components/notifications.vue
index c5ab284df..d8b8eab21 100644
--- a/src/client/app/desktop/views/components/notifications.vue
+++ b/src/client/app/desktop/views/components/notifications.vue
@@ -11,7 +11,7 @@
 					<div class="text">
 						<p>
 							<mk-reaction-icon :reaction="notification.reaction"/>
-							<router-link :to="`/@${getAcct(notification.user)}`" v-user-preview="notification.user.id">{{ notification.user.name }}</router-link>
+							<router-link :to="`/@${getAcct(notification.user)}`" v-user-preview="notification.user.id">{{ getUserName(notification.user) }}</router-link>
 						</p>
 						<router-link class="post-ref" :to="`/@${getAcct(notification.post.user)}/${notification.post.id}`">
 							%fa:quote-left%{{ getPostSummary(notification.post) }}%fa:quote-right%
@@ -24,7 +24,7 @@
 					</router-link>
 					<div class="text">
 						<p>%fa:retweet%
-							<router-link :to="`/@${getAcct(notification.post.user)}`" v-user-preview="notification.post.userId">{{ notification.post.user.name }}</router-link>
+							<router-link :to="`/@${getAcct(notification.post.user)}`" v-user-preview="notification.post.userId">{{ getUserName(notification.post.user) }}</router-link>
 						</p>
 						<router-link class="post-ref" :to="`/@${getAcct(notification.post.user)}/${notification.post.id}`">
 							%fa:quote-left%{{ getPostSummary(notification.post.repost) }}%fa:quote-right%
@@ -37,7 +37,7 @@
 					</router-link>
 					<div class="text">
 						<p>%fa:quote-left%
-							<router-link :to="`/@${getAcct(notification.post.user)}`" v-user-preview="notification.post.userId">{{ notification.post.user.name }}</router-link>
+							<router-link :to="`/@${getAcct(notification.post.user)}`" v-user-preview="notification.post.userId">{{ getUserName(notification.post.user) }}</router-link>
 						</p>
 						<router-link class="post-preview" :to="`/@${getAcct(notification.post.user)}/${notification.post.id}`">{{ getPostSummary(notification.post) }}</router-link>
 					</div>
@@ -48,7 +48,7 @@
 					</router-link>
 					<div class="text">
 						<p>%fa:user-plus%
-							<router-link :to="`/@${getAcct(notification.user)}`" v-user-preview="notification.user.id">{{ notification.user.name }}</router-link>
+							<router-link :to="`/@${getAcct(notification.user)}`" v-user-preview="notification.user.id">{{ getUserName(notification.user) }}</router-link>
 						</p>
 					</div>
 				</template>
@@ -58,7 +58,7 @@
 					</router-link>
 					<div class="text">
 						<p>%fa:reply%
-							<router-link :to="`/@${getAcct(notification.post.user)}`" v-user-preview="notification.post.userId">{{ notification.post.user.name }}</router-link>
+							<router-link :to="`/@${getAcct(notification.post.user)}`" v-user-preview="notification.post.userId">{{ getUserName(notification.post.user) }}</router-link>
 						</p>
 						<router-link class="post-preview" :to="`/@${getAcct(notification.post.user)}/${notification.post.id}`">{{ getPostSummary(notification.post) }}</router-link>
 					</div>
@@ -69,7 +69,7 @@
 					</router-link>
 					<div class="text">
 						<p>%fa:at%
-							<router-link :to="`/@${getAcct(notification.post.user)}`" v-user-preview="notification.post.userId">{{ notification.post.user.name }}</router-link>
+							<router-link :to="`/@${getAcct(notification.post.user)}`" v-user-preview="notification.post.userId">{{ getUserName(notification.post.user) }}</router-link>
 						</p>
 						<a class="post-preview" :href="`/@${getAcct(notification.post.user)}/${notification.post.id}`">{{ getPostSummary(notification.post) }}</a>
 					</div>
@@ -79,7 +79,7 @@
 						<img class="avatar" :src="`${notification.user.avatarUrl}?thumbnail&size=48`" alt="avatar"/>
 					</router-link>
 					<div class="text">
-						<p>%fa:chart-pie%<a :href="`/@${getAcct(notification.user)}`" v-user-preview="notification.user.id">{{ notification.user.name }}</a></p>
+						<p>%fa:chart-pie%<a :href="`/@${getAcct(notification.user)}`" v-user-preview="notification.user.id">{{ getUserName(notification.user) }}</a></p>
 						<router-link class="post-ref" :to="`/@${getAcct(notification.post.user)}/${notification.post.id}`">
 							%fa:quote-left%{{ getPostSummary(notification.post) }}%fa:quote-right%
 						</router-link>
@@ -104,6 +104,7 @@
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
 import getPostSummary from '../../../../../renderers/get-post-summary';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	data() {
@@ -154,6 +155,7 @@ export default Vue.extend({
 	},
 	methods: {
 		getAcct,
+		getUserName,
 		fetchMoreNotifications() {
 			this.fetchingMoreNotifications = true;
 
diff --git a/src/client/app/desktop/views/components/post-detail.sub.vue b/src/client/app/desktop/views/components/post-detail.sub.vue
index 59bc9ce0c..496003eb8 100644
--- a/src/client/app/desktop/views/components/post-detail.sub.vue
+++ b/src/client/app/desktop/views/components/post-detail.sub.vue
@@ -6,7 +6,7 @@
 	<div class="main">
 		<header>
 			<div class="left">
-				<router-link class="name" :to="`/@${acct}`" v-user-preview="post.userId">{{ post.user.name }}</router-link>
+				<router-link class="name" :to="`/@${acct}`" v-user-preview="post.userId">{{ getUserName(post.user) }}</router-link>
 				<span class="username">@{{ acct }}</span>
 			</div>
 			<div class="right">
@@ -29,6 +29,7 @@
 import Vue from 'vue';
 import dateStringify from '../../../common/scripts/date-stringify';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['post'],
@@ -36,6 +37,9 @@ export default Vue.extend({
 		acct() {
 			return getAcct(this.post.user);
 		},
+		name() {
+			return getUserName(this.post.user);
+		},
 		title(): string {
 			return dateStringify(this.post.createdAt);
 		}
diff --git a/src/client/app/desktop/views/components/post-detail.vue b/src/client/app/desktop/views/components/post-detail.vue
index 8000ce2e6..1a3c0d1b6 100644
--- a/src/client/app/desktop/views/components/post-detail.vue
+++ b/src/client/app/desktop/views/components/post-detail.vue
@@ -22,7 +22,7 @@
 				<img class="avatar" :src="`${post.user.avatarUrl}?thumbnail&size=32`" alt="avatar"/>
 			</router-link>
 			%fa:retweet%
-			<router-link class="name" :href="`/@${acct}`">{{ post.user.name }}</router-link>
+			<router-link class="name" :href="`/@${acct}`">{{ getUserName(post.user) }}</router-link>
 			がRepost
 		</p>
 	</div>
@@ -31,7 +31,7 @@
 			<img class="avatar" :src="`${p.user.avatarUrl}?thumbnail&size=64`" alt="avatar" v-user-preview="p.user.id"/>
 		</router-link>
 		<header>
-			<router-link class="name" :to="`/@${pAcct}`" v-user-preview="p.user.id">{{ p.user.name }}</router-link>
+			<router-link class="name" :to="`/@${pAcct}`" v-user-preview="p.user.id">{{ getUserName(p.user) }}</router-link>
 			<span class="username">@{{ pAcct }}</span>
 			<router-link class="time" :to="`/@${pAcct}/${p.id}`">
 				<mk-time :time="p.createdAt"/>
@@ -79,6 +79,7 @@
 import Vue from 'vue';
 import dateStringify from '../../../common/scripts/date-stringify';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 import parse from '../../../../../text/parse';
 
 import MkPostFormWindow from './post-form-window.vue';
@@ -133,9 +134,15 @@ export default Vue.extend({
 		acct(): string {
 			return getAcct(this.post.user);
 		},
+		name(): string {
+			return getUserName(this.post.user);
+		},
 		pAcct(): string {
 			return getAcct(this.p.user);
 		},
+		pName(): string {
+			return getUserName(this.p.user);
+		},
 		urls(): string[] {
 			if (this.p.text) {
 				const ast = parse(this.p.text);
diff --git a/src/client/app/desktop/views/components/post-preview.vue b/src/client/app/desktop/views/components/post-preview.vue
index 7129f67b3..99d9442d9 100644
--- a/src/client/app/desktop/views/components/post-preview.vue
+++ b/src/client/app/desktop/views/components/post-preview.vue
@@ -5,7 +5,7 @@
 	</router-link>
 	<div class="main">
 		<header>
-			<router-link class="name" :to="`/@${acct}`" v-user-preview="post.userId">{{ post.user.name }}</router-link>
+			<router-link class="name" :to="`/@${acct}`" v-user-preview="post.userId">{{ name }}</router-link>
 			<span class="username">@{{ acct }}</span>
 			<router-link class="time" :to="`/@${acct}/${post.id}`">
 				<mk-time :time="post.createdAt"/>
@@ -22,6 +22,7 @@
 import Vue from 'vue';
 import dateStringify from '../../../common/scripts/date-stringify';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['post'],
@@ -29,6 +30,9 @@ export default Vue.extend({
 		acct() {
 			return getAcct(this.post.user);
 		},
+		name() {
+			return getUserName(this.post.user);
+		},
 		title(): string {
 			return dateStringify(this.post.createdAt);
 		}
diff --git a/src/client/app/desktop/views/components/posts.post.sub.vue b/src/client/app/desktop/views/components/posts.post.sub.vue
index dffecb89c..a9cd0a927 100644
--- a/src/client/app/desktop/views/components/posts.post.sub.vue
+++ b/src/client/app/desktop/views/components/posts.post.sub.vue
@@ -5,7 +5,7 @@
 	</router-link>
 	<div class="main">
 		<header>
-			<router-link class="name" :to="`/@${acct}`" v-user-preview="post.userId">{{ post.user.name }}</router-link>
+			<router-link class="name" :to="`/@${acct}`" v-user-preview="post.userId">{{ name }}</router-link>
 			<span class="username">@{{ acct }}</span>
 			<router-link class="created-at" :to="`/@${acct}/${post.id}`">
 				<mk-time :time="post.createdAt"/>
@@ -22,6 +22,7 @@
 import Vue from 'vue';
 import dateStringify from '../../../common/scripts/date-stringify';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['post'],
@@ -29,6 +30,9 @@ export default Vue.extend({
 		acct() {
 			return getAcct(this.post.user);
 		},
+		name(): string {
+			return getUserName(this.post.user);
+		},
 		title(): string {
 			return dateStringify(this.post.createdAt);
 		}
diff --git a/src/client/app/desktop/views/components/posts.post.vue b/src/client/app/desktop/views/components/posts.post.vue
index 9a13dd687..17fe33042 100644
--- a/src/client/app/desktop/views/components/posts.post.vue
+++ b/src/client/app/desktop/views/components/posts.post.vue
@@ -10,7 +10,7 @@
 			</router-link>
 			%fa:retweet%
 			<span>{{ '%i18n:desktop.tags.mk-timeline-post.reposted-by%'.substr(0, '%i18n:desktop.tags.mk-timeline-post.reposted-by%'.indexOf('{')) }}</span>
-			<a class="name" :href="`/@${acct}`" v-user-preview="post.userId">{{ post.user.name }}</a>
+			<a class="name" :href="`/@${acct}`" v-user-preview="post.userId">{{ getUserName(post.user) }}</a>
 			<span>{{ '%i18n:desktop.tags.mk-timeline-post.reposted-by%'.substr('%i18n:desktop.tags.mk-timeline-post.reposted-by%'.indexOf('}') + 1) }}</span>
 		</p>
 		<mk-time :time="post.createdAt"/>
@@ -86,6 +86,7 @@
 import Vue from 'vue';
 import dateStringify from '../../../common/scripts/date-stringify';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 import parse from '../../../../../text/parse';
 
 import MkPostFormWindow from './post-form-window.vue';
@@ -124,6 +125,9 @@ export default Vue.extend({
 		acct(): string {
 			return getAcct(this.p.user);
 		},
+		name(): string {
+			return getUserName(this.p.user);
+		},
 		isRepost(): boolean {
 			return (this.post.repost &&
 				this.post.text == null &&
diff --git a/src/client/app/desktop/views/components/settings.mute.vue b/src/client/app/desktop/views/components/settings.mute.vue
index c87f973fa..6bdc76653 100644
--- a/src/client/app/desktop/views/components/settings.mute.vue
+++ b/src/client/app/desktop/views/components/settings.mute.vue
@@ -5,7 +5,7 @@
 	</div>
 	<div class="users" v-if="users.length != 0">
 		<div v-for="user in users" :key="user.id">
-			<p><b>{{ user.name }}</b> @{{ getAcct(user) }}</p>
+			<p><b>{{ getUserName(user) }}</b> @{{ getAcct(user) }}</p>
 		</div>
 	</div>
 </div>
@@ -14,6 +14,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	data() {
@@ -23,7 +24,8 @@ export default Vue.extend({
 		};
 	},
 	methods: {
-		getAcct
+		getAcct,
+		getUserName
 	},
 	mounted() {
 		(this as any).api('mute/list').then(x => {
diff --git a/src/client/app/desktop/views/components/settings.profile.vue b/src/client/app/desktop/views/components/settings.profile.vue
index ba86286f8..28be48e0a 100644
--- a/src/client/app/desktop/views/components/settings.profile.vue
+++ b/src/client/app/desktop/views/components/settings.profile.vue
@@ -42,7 +42,7 @@ export default Vue.extend({
 		};
 	},
 	created() {
-		this.name = (this as any).os.i.name;
+		this.name = (this as any).os.i.name || '';
 		this.location = (this as any).os.i.account.profile.location;
 		this.description = (this as any).os.i.description;
 		this.birthday = (this as any).os.i.account.profile.birthday;
@@ -53,7 +53,7 @@ export default Vue.extend({
 		},
 		save() {
 			(this as any).api('i/update', {
-				name: this.name,
+				name: this.name || null,
 				location: this.location || null,
 				description: this.description || null,
 				birthday: this.birthday || null
diff --git a/src/client/app/desktop/views/components/ui.header.vue b/src/client/app/desktop/views/components/ui.header.vue
index 448d04d26..7d93847fa 100644
--- a/src/client/app/desktop/views/components/ui.header.vue
+++ b/src/client/app/desktop/views/components/ui.header.vue
@@ -4,7 +4,7 @@
 	<div class="main" ref="main">
 		<div class="backdrop"></div>
 		<div class="main">
-			<p ref="welcomeback" v-if="os.isSignedIn">おかえりなさい、<b>{{ os.i.name }}</b>さん</p>
+			<p ref="welcomeback" v-if="os.isSignedIn">おかえりなさい、<b>{{ name }}</b>さん</p>
 			<div class="container" ref="mainContainer">
 				<div class="left">
 					<x-nav/>
@@ -33,7 +33,14 @@ import XNotifications from './ui.header.notifications.vue';
 import XPost from './ui.header.post.vue';
 import XClock from './ui.header.clock.vue';
 
+import getUserName from '../../../../../renderers/get-user-name';
+
 export default Vue.extend({
+	computed: {
+		name() {
+			return getUserName(this.os.i);
+		}
+	},
 	components: {
 		XNav,
 		XSearch,
diff --git a/src/client/app/desktop/views/components/users-list.item.vue b/src/client/app/desktop/views/components/users-list.item.vue
index 2d7d4dc72..c7a132ecf 100644
--- a/src/client/app/desktop/views/components/users-list.item.vue
+++ b/src/client/app/desktop/views/components/users-list.item.vue
@@ -5,7 +5,7 @@
 	</router-link>
 	<div class="main">
 		<header>
-			<router-link class="name" :to="`/@${acct}`" v-user-preview="user.id">{{ user.name }}</router-link>
+			<router-link class="name" :to="`/@${acct}`" v-user-preview="user.id">{{ name }}</router-link>
 			<span class="username">@{{ acct }}</span>
 		</header>
 		<div class="body">
@@ -20,12 +20,16 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['user'],
 	computed: {
 		acct() {
 			return getAcct(this.user);
+		},
+		name() {
+			return getUserName(this.user);
 		}
 	}
 });
diff --git a/src/client/app/desktop/views/pages/messaging-room.vue b/src/client/app/desktop/views/pages/messaging-room.vue
index 1e61f3ce1..1cc8d8a77 100644
--- a/src/client/app/desktop/views/pages/messaging-room.vue
+++ b/src/client/app/desktop/views/pages/messaging-room.vue
@@ -8,6 +8,7 @@
 import Vue from 'vue';
 import Progress from '../../../common/scripts/loading';
 import parseAcct from '../../../../../acct/parse';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	data() {
@@ -34,7 +35,7 @@ export default Vue.extend({
 				this.user = user;
 				this.fetching = false;
 
-				document.title = 'メッセージ: ' + this.user.name;
+				document.title = 'メッセージ: ' + getUserName(this.user);
 
 				Progress.done();
 			});
diff --git a/src/client/app/desktop/views/pages/user/user.followers-you-know.vue b/src/client/app/desktop/views/pages/user/user.followers-you-know.vue
index 7497acd0e..16625b689 100644
--- a/src/client/app/desktop/views/pages/user/user.followers-you-know.vue
+++ b/src/client/app/desktop/views/pages/user/user.followers-you-know.vue
@@ -4,7 +4,7 @@
 	<p class="initializing" v-if="fetching">%fa:spinner .pulse .fw%%i18n:desktop.tags.mk-user.followers-you-know.loading%<mk-ellipsis/></p>
 	<div v-if="!fetching && users.length > 0">
 	<router-link v-for="user in users" :to="`/@${getAcct(user)}`" :key="user.id">
-		<img :src="`${user.avatarUrl}?thumbnail&size=64`" :alt="user.name" v-user-preview="user.id"/>
+		<img :src="`${user.avatarUrl}?thumbnail&size=64`" :alt="getUserName(user)" v-user-preview="user.id"/>
 	</router-link>
 	</div>
 	<p class="empty" v-if="!fetching && users.length == 0">%i18n:desktop.tags.mk-user.followers-you-know.no-users%</p>
@@ -14,6 +14,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../../acct/render';
+import getUserName from '../../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['user'],
@@ -24,7 +25,8 @@ export default Vue.extend({
 		};
 	},
 	method() {
-		getAcct
+		getAcct,
+		getUserName
 	},
 	mounted() {
 		(this as any).api('users/followers', {
diff --git a/src/client/app/desktop/views/pages/user/user.header.vue b/src/client/app/desktop/views/pages/user/user.header.vue
index d30f423d5..5c6746d5d 100644
--- a/src/client/app/desktop/views/pages/user/user.header.vue
+++ b/src/client/app/desktop/views/pages/user/user.header.vue
@@ -7,7 +7,7 @@
 	<div class="container">
 		<img class="avatar" :src="`${user.avatarUrl}?thumbnail&size=150`" alt="avatar"/>
 		<div class="title">
-			<p class="name">{{ user.name }}</p>
+			<p class="name">{{ name }}</p>
 			<p class="username">@{{ acct }}</p>
 			<p class="location" v-if="user.host === null && user.account.profile.location">%fa:map-marker%{{ user.account.profile.location }}</p>
 		</div>
@@ -23,12 +23,16 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../../acct/render';
+import getUserName from '../../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['user'],
 	computed: {
 		acct() {
 			return getAcct(this.user);
+		},
+		name() {
+			return getUserName(this.user);
 		}
 	},
 	mounted() {
diff --git a/src/client/app/desktop/views/pages/user/user.vue b/src/client/app/desktop/views/pages/user/user.vue
index 02ddc2421..d07b462b5 100644
--- a/src/client/app/desktop/views/pages/user/user.vue
+++ b/src/client/app/desktop/views/pages/user/user.vue
@@ -10,6 +10,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import parseAcct from '../../../../../../acct/parse';
+import getUserName from '../../../../../../renderers/get-user-name';
 import Progress from '../../../../common/scripts/loading';
 import XHeader from './user.header.vue';
 import XHome from './user.home.vue';
@@ -44,7 +45,7 @@ export default Vue.extend({
 				this.user = user;
 				this.fetching = false;
 				Progress.done();
-				document.title = user.name + ' | Misskey';
+				document.title = getUserName(user) + ' | Misskey';
 			});
 		}
 	}
diff --git a/src/client/app/desktop/views/widgets/channel.channel.post.vue b/src/client/app/desktop/views/widgets/channel.channel.post.vue
index e10e9c4f7..fa6d8c34a 100644
--- a/src/client/app/desktop/views/widgets/channel.channel.post.vue
+++ b/src/client/app/desktop/views/widgets/channel.channel.post.vue
@@ -2,7 +2,7 @@
 <div class="post">
 	<header>
 		<a class="index" @click="reply">{{ post.index }}:</a>
-		<router-link class="name" :to="`/@${acct}`" v-user-preview="post.user.id"><b>{{ post.user.name }}</b></router-link>
+		<router-link class="name" :to="`/@${acct}`" v-user-preview="post.user.id"><b>{{ name }}</b></router-link>
 		<span>ID:<i>{{ acct }}</i></span>
 	</header>
 	<div>
@@ -20,12 +20,16 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['post'],
 	computed: {
 		acct() {
 			return getAcct(this.post.user);
+		},
+		name() {
+			return getUserName(this.post.user);
 		}
 	},
 	methods: {
diff --git a/src/client/app/desktop/views/widgets/profile.vue b/src/client/app/desktop/views/widgets/profile.vue
index 83cd67b50..98e42222e 100644
--- a/src/client/app/desktop/views/widgets/profile.vue
+++ b/src/client/app/desktop/views/widgets/profile.vue
@@ -15,19 +15,26 @@
 		title="クリックでアバター編集"
 		v-user-preview="os.i.id"
 	/>
-	<router-link class="name" :to="`/@${os.i.username}`">{{ os.i.name }}</router-link>
+	<router-link class="name" :to="`/@${os.i.username}`">{{ name }}</router-link>
 	<p class="username">@{{ os.i.username }}</p>
 </div>
 </template>
 
 <script lang="ts">
 import define from '../../../common/define-widget';
+import getUserName from '../../../../../renderers/get-user-name';
+
 export default define({
 	name: 'profile',
 	props: () => ({
 		design: 0
 	})
 }).extend({
+	computed: {
+		name() {
+			return getUserName(this.os.i);
+		}
+	},
 	methods: {
 		func() {
 			if (this.props.design == 2) {
diff --git a/src/client/app/desktop/views/widgets/users.vue b/src/client/app/desktop/views/widgets/users.vue
index 6f6a10157..a5dabb68f 100644
--- a/src/client/app/desktop/views/widgets/users.vue
+++ b/src/client/app/desktop/views/widgets/users.vue
@@ -11,7 +11,7 @@
 				<img class="avatar" :src="`${_user.avatarUrl}?thumbnail&size=42`" alt="" v-user-preview="_user.id"/>
 			</router-link>
 			<div class="body">
-				<router-link class="name" :to="`/@${getAcct(_user)}`" v-user-preview="_user.id">{{ _user.name }}</router-link>
+				<router-link class="name" :to="`/@${getAcct(_user)}`" v-user-preview="_user.id">{{ getUserName(_user) }}</router-link>
 				<p class="username">@{{ getAcct(_user) }}</p>
 			</div>
 			<mk-follow-button :user="_user"/>
@@ -24,6 +24,7 @@
 <script lang="ts">
 import define from '../../../common/define-widget';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 const limit = 3;
 
@@ -45,6 +46,7 @@ export default define({
 	},
 	methods: {
 		getAcct,
+		getUserName,
 		func() {
 			this.props.compact = !this.props.compact;
 		},
diff --git a/src/client/app/mobile/views/components/notification-preview.vue b/src/client/app/mobile/views/components/notification-preview.vue
index 77abd3c0e..0492c5d86 100644
--- a/src/client/app/mobile/views/components/notification-preview.vue
+++ b/src/client/app/mobile/views/components/notification-preview.vue
@@ -3,7 +3,7 @@
 	<template v-if="notification.type == 'reaction'">
 		<img class="avatar" :src="`${notification.user.avatarUrl}?thumbnail&size=64`" alt="avatar"/>
 		<div class="text">
-			<p><mk-reaction-icon :reaction="notification.reaction"/>{{ notification.user.name }}</p>
+			<p><mk-reaction-icon :reaction="notification.reaction"/>{{ name }}</p>
 			<p class="post-ref">%fa:quote-left%{{ getPostSummary(notification.post) }}%fa:quote-right%</p>
 		</div>
 	</template>
@@ -11,7 +11,7 @@
 	<template v-if="notification.type == 'repost'">
 		<img class="avatar" :src="`${notification.post.user.avatarUrl}?thumbnail&size=64`" alt="avatar"/>
 		<div class="text">
-			<p>%fa:retweet%{{ notification.post.user.name }}</p>
+			<p>%fa:retweet%{{ posterName }}</p>
 			<p class="post-ref">%fa:quote-left%{{ getPostSummary(notification.post.repost) }}%fa:quote-right%</p>
 		</div>
 	</template>
@@ -19,7 +19,7 @@
 	<template v-if="notification.type == 'quote'">
 		<img class="avatar" :src="`${notification.post.user.avatarUrl}?thumbnail&size=64`" alt="avatar"/>
 		<div class="text">
-			<p>%fa:quote-left%{{ notification.post.user.name }}</p>
+			<p>%fa:quote-left%{{ posterName }}</p>
 			<p class="post-preview">{{ getPostSummary(notification.post) }}</p>
 		</div>
 	</template>
@@ -27,14 +27,14 @@
 	<template v-if="notification.type == 'follow'">
 		<img class="avatar" :src="`${notification.user.avatarUrl}?thumbnail&size=64`" alt="avatar"/>
 		<div class="text">
-			<p>%fa:user-plus%{{ notification.user.name }}</p>
+			<p>%fa:user-plus%{{ name }}</p>
 		</div>
 	</template>
 
 	<template v-if="notification.type == 'reply'">
 		<img class="avatar" :src="`${notification.post.user.avatarUrl}?thumbnail&size=64`" alt="avatar"/>
 		<div class="text">
-			<p>%fa:reply%{{ notification.post.user.name }}</p>
+			<p>%fa:reply%{{ posterName }}</p>
 			<p class="post-preview">{{ getPostSummary(notification.post) }}</p>
 		</div>
 	</template>
@@ -42,7 +42,7 @@
 	<template v-if="notification.type == 'mention'">
 		<img class="avatar" :src="`${notification.post.user.avatarUrl}?thumbnail&size=64`" alt="avatar"/>
 		<div class="text">
-			<p>%fa:at%{{ notification.post.user.name }}</p>
+			<p>%fa:at%{{ posterName }}</p>
 			<p class="post-preview">{{ getPostSummary(notification.post) }}</p>
 		</div>
 	</template>
@@ -50,7 +50,7 @@
 	<template v-if="notification.type == 'poll_vote'">
 		<img class="avatar" :src="`${notification.user.avatarUrl}?thumbnail&size=64`" alt="avatar"/>
 		<div class="text">
-			<p>%fa:chart-pie%{{ notification.user.name }}</p>
+			<p>%fa:chart-pie%{{ name }}</p>
 			<p class="post-ref">%fa:quote-left%{{ getPostSummary(notification.post) }}%fa:quote-right%</p>
 		</div>
 	</template>
@@ -60,9 +60,18 @@
 <script lang="ts">
 import Vue from 'vue';
 import getPostSummary from '../../../../../renderers/get-post-summary';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['notification'],
+	computed: {
+		name() {
+			return getUserName(this.notification.user);
+		},
+		posterName() {
+			return getUserName(this.notification.post.user);
+		}
+	},
 	data() {
 		return {
 			getPostSummary
diff --git a/src/client/app/mobile/views/components/notification.vue b/src/client/app/mobile/views/components/notification.vue
index 189d7195f..62a0e6425 100644
--- a/src/client/app/mobile/views/components/notification.vue
+++ b/src/client/app/mobile/views/components/notification.vue
@@ -8,7 +8,7 @@
 		<div class="text">
 			<p>
 				<mk-reaction-icon :reaction="notification.reaction"/>
-				<router-link :to="`/@${acct}`">{{ notification.user.name }}</router-link>
+				<router-link :to="`/@${acct}`">{{ getUserName(notification.user) }}</router-link>
 			</p>
 			<router-link class="post-ref" :to="`/@${acct}/${notification.post.id}`">
 				%fa:quote-left%{{ getPostSummary(notification.post) }}
@@ -25,7 +25,7 @@
 		<div class="text">
 			<p>
 				%fa:retweet%
-				<router-link :to="`/@${acct}`">{{ notification.post.user.name }}</router-link>
+				<router-link :to="`/@${acct}`">{{ getUserName(notification.post.user) }}</router-link>
 			</p>
 			<router-link class="post-ref" :to="`/@${acct}/${notification.post.id}`">
 				%fa:quote-left%{{ getPostSummary(notification.post.repost) }}%fa:quote-right%
@@ -45,7 +45,7 @@
 		<div class="text">
 			<p>
 				%fa:user-plus%
-				<router-link :to="`/@${acct}`">{{ notification.user.name }}</router-link>
+				<router-link :to="`/@${acct}`">{{ getUserName(notification.user) }}</router-link>
 			</p>
 		</div>
 	</div>
@@ -66,7 +66,7 @@
 		<div class="text">
 			<p>
 				%fa:chart-pie%
-				<router-link :to="`/@${acct}`">{{ notification.user.name }}</router-link>
+				<router-link :to="`/@${acct}`">{{ getUserName(notification.user) }}</router-link>
 			</p>
 			<router-link class="post-ref" :to="`/@${acct}/${notification.post.id}`">
 				%fa:quote-left%{{ getPostSummary(notification.post) }}%fa:quote-right%
@@ -80,12 +80,19 @@
 import Vue from 'vue';
 import getPostSummary from '../../../../../renderers/get-post-summary';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['notification'],
 	computed: {
 		acct() {
 			return getAcct(this.notification.user);
+		},
+		name() {
+			return getUserName(this.notification.user);
+		},
+		posterName() {
+ 			return getUserName(this.notification.post.user);
 		}
 	},
 	data() {
diff --git a/src/client/app/mobile/views/components/post-card.vue b/src/client/app/mobile/views/components/post-card.vue
index 38d4522d2..68a42ef24 100644
--- a/src/client/app/mobile/views/components/post-card.vue
+++ b/src/client/app/mobile/views/components/post-card.vue
@@ -2,7 +2,7 @@
 <div class="mk-post-card">
 	<a :href="`/@${acct}/${post.id}`">
 		<header>
-			<img :src="`${acct}?thumbnail&size=64`" alt="avatar"/><h3>{{ post.user.name }}</h3>
+			<img :src="`${acct}?thumbnail&size=64`" alt="avatar"/><h3>{{ name }}</h3>
 		</header>
 		<div>
 			{{ text }}
@@ -16,6 +16,7 @@
 import Vue from 'vue';
 import summary from '../../../../../renderers/get-post-summary';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['post'],
@@ -23,6 +24,9 @@ export default Vue.extend({
 		acct() {
 			return getAcct(this.post.user);
 		},
+		name() {
+			return getUserName(this.post.user);
+		},
 		text(): string {
 			return summary(this.post);
 		}
diff --git a/src/client/app/mobile/views/components/post-detail.sub.vue b/src/client/app/mobile/views/components/post-detail.sub.vue
index 7ff9f1aab..98d6a14ca 100644
--- a/src/client/app/mobile/views/components/post-detail.sub.vue
+++ b/src/client/app/mobile/views/components/post-detail.sub.vue
@@ -5,7 +5,7 @@
 	</router-link>
 	<div class="main">
 		<header>
-			<router-link class="name" :to="`/@${acct}`">{{ post.user.name }}</router-link>
+			<router-link class="name" :to="`/@${acct}`">{{ getUserName(post.user) }}</router-link>
 			<span class="username">@{{ acct }}</span>
 			<router-link class="time" :to="`/@${acct}/${post.id}`">
 				<mk-time :time="post.createdAt"/>
@@ -21,12 +21,16 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['post'],
 	computed: {
 		acct() {
 			return getAcct(this.post.user);
+		},
+		name() {
+			return getUserName(this.post.user);
 		}
 	}
 });
diff --git a/src/client/app/mobile/views/components/post-detail.vue b/src/client/app/mobile/views/components/post-detail.vue
index ed394acd3..0226ce081 100644
--- a/src/client/app/mobile/views/components/post-detail.vue
+++ b/src/client/app/mobile/views/components/post-detail.vue
@@ -22,7 +22,7 @@
 			</router-link>
 			%fa:retweet%
 			<router-link class="name" :to="`/@${acct}`">
-				{{ post.user.name }}
+				{{ name }}
 			</router-link>
 			がRepost
 		</p>
@@ -33,7 +33,7 @@
 				<img class="avatar" :src="`${p.user.avatarUrl}?thumbnail&size=64`" alt="avatar"/>
 			</router-link>
 			<div>
-				<router-link class="name" :to="`/@${pAcct}`">{{ p.user.name }}</router-link>
+				<router-link class="name" :to="`/@${pAcct}`">{{ pName }}</router-link>
 				<span class="username">@{{ pAcct }}</span>
 			</div>
 		</header>
@@ -81,6 +81,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 import parse from '../../../../../text/parse';
 
 import MkPostMenu from '../../../common/views/components/post-menu.vue';
@@ -114,9 +115,15 @@ export default Vue.extend({
 		acct(): string {
 			return getAcct(this.post.user);
 		},
+		name(): string {
+			return getUserName(this.post.user);
+		},
 		pAcct(): string {
 			return getAcct(this.p.user);
 		},
+		pName(): string {
+			return getUserName(this.p.user);
+		},
 		isRepost(): boolean {
 			return (this.post.repost &&
 				this.post.text == null &&
diff --git a/src/client/app/mobile/views/components/post-preview.vue b/src/client/app/mobile/views/components/post-preview.vue
index 81b0c22bf..96bd4d5c1 100644
--- a/src/client/app/mobile/views/components/post-preview.vue
+++ b/src/client/app/mobile/views/components/post-preview.vue
@@ -5,7 +5,7 @@
 	</router-link>
 	<div class="main">
 		<header>
-			<router-link class="name" :to="`/@${acct}`">{{ post.user.name }}</router-link>
+			<router-link class="name" :to="`/@${acct}`">{{ name }}</router-link>
 			<span class="username">@{{ acct }}</span>
 			<router-link class="time" :to="`/@${acct}/${post.id}`">
 				<mk-time :time="post.createdAt"/>
@@ -21,12 +21,16 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['post'],
 	computed: {
 		acct() {
 			return getAcct(this.post.user);
+		},
+		name() {
+			return getUserName(this.post.user);
 		}
 	}
 });
diff --git a/src/client/app/mobile/views/components/post.sub.vue b/src/client/app/mobile/views/components/post.sub.vue
index 85ddb9188..909d5cb59 100644
--- a/src/client/app/mobile/views/components/post.sub.vue
+++ b/src/client/app/mobile/views/components/post.sub.vue
@@ -5,7 +5,7 @@
 	</router-link>
 	<div class="main">
 		<header>
-			<router-link class="name" :to="`/@${acct}`">{{ post.user.name }}</router-link>
+			<router-link class="name" :to="`/@${acct}`">{{ getUserName(post.user) }}</router-link>
 			<span class="username">@{{ acct }}</span>
 			<router-link class="created-at" :to="`/@${acct}/${post.id}`">
 				<mk-time :time="post.createdAt"/>
@@ -21,12 +21,16 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['post'],
 	computed: {
 		acct() {
 			return getAcct(this.post.user);
+		},
+		name() {
+			return getUserName(this.post.user);
 		}
 	}
 });
diff --git a/src/client/app/mobile/views/components/post.vue b/src/client/app/mobile/views/components/post.vue
index 1454bc939..eee1e80fd 100644
--- a/src/client/app/mobile/views/components/post.vue
+++ b/src/client/app/mobile/views/components/post.vue
@@ -10,7 +10,7 @@
 			</router-link>
 			%fa:retweet%
 			<span>{{ '%i18n:mobile.tags.mk-timeline-post.reposted-by%'.substr(0, '%i18n:mobile.tags.mk-timeline-post.reposted-by%'.indexOf('{')) }}</span>
-			<router-link class="name" :to="`/@${acct}`">{{ post.user.name }}</router-link>
+			<router-link class="name" :to="`/@${acct}`">{{ name }}</router-link>
 			<span>{{ '%i18n:mobile.tags.mk-timeline-post.reposted-by%'.substr('%i18n:mobile.tags.mk-timeline-post.reposted-by%'.indexOf('}') + 1) }}</span>
 		</p>
 		<mk-time :time="post.createdAt"/>
@@ -21,7 +21,7 @@
 		</router-link>
 		<div class="main">
 			<header>
-				<router-link class="name" :to="`/@${pAcct}`">{{ p.user.name }}</router-link>
+				<router-link class="name" :to="`/@${pAcct}`">{{ pName }}</router-link>
 				<span class="is-bot" v-if="p.user.host === null && p.user.account.isBot">bot</span>
 				<span class="username">@{{ pAcct }}</span>
 				<div class="info">
@@ -78,6 +78,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 import parse from '../../../../../text/parse';
 
 import MkPostMenu from '../../../common/views/components/post-menu.vue';
@@ -102,9 +103,15 @@ export default Vue.extend({
 		acct(): string {
 			return getAcct(this.post.user);
 		},
+		name(): string {
+			return getUserName(this.post.user);
+		},
 		pAcct(): string {
 			return getAcct(this.p.user);
 		},
+		pName(): string {
+			return getUserName(this.p.user);
+		},
 		isRepost(): boolean {
 			return (this.post.repost &&
 				this.post.text == null &&
diff --git a/src/client/app/mobile/views/components/ui.header.vue b/src/client/app/mobile/views/components/ui.header.vue
index 2bf47a90a..fd4f31fd9 100644
--- a/src/client/app/mobile/views/components/ui.header.vue
+++ b/src/client/app/mobile/views/components/ui.header.vue
@@ -3,7 +3,7 @@
 	<mk-special-message/>
 	<div class="main" ref="main">
 		<div class="backdrop"></div>
-		<p ref="welcomeback" v-if="os.isSignedIn">おかえりなさい、<b>{{ os.i.name }}</b>さん</p>
+		<p ref="welcomeback" v-if="os.isSignedIn">おかえりなさい、<b>{{ name }}</b>さん</p>
 		<div class="content" ref="mainContainer">
 			<button class="nav" @click="$parent.isDrawerOpening = true">%fa:bars%</button>
 			<template v-if="hasUnreadNotifications || hasUnreadMessagingMessages || hasGameInvitations">%fa:circle%</template>
@@ -19,9 +19,15 @@
 <script lang="ts">
 import Vue from 'vue';
 import * as anime from 'animejs';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['func'],
+	computed: {
+		name() {
+			return getUserName(this.os.i);
+		}
+	},
 	data() {
 		return {
 			hasUnreadNotifications: false,
diff --git a/src/client/app/mobile/views/components/ui.nav.vue b/src/client/app/mobile/views/components/ui.nav.vue
index a923774a7..61dd8ca9d 100644
--- a/src/client/app/mobile/views/components/ui.nav.vue
+++ b/src/client/app/mobile/views/components/ui.nav.vue
@@ -11,7 +11,7 @@
 		<div class="body" v-if="isOpen">
 			<router-link class="me" v-if="os.isSignedIn" :to="`/@${os.i.username}`">
 				<img class="avatar" :src="`${os.i.avatarUrl}?thumbnail&size=128`" alt="avatar"/>
-				<p class="name">{{ os.i.name }}</p>
+				<p class="name">{{ name }}</p>
 			</router-link>
 			<div class="links">
 				<ul>
@@ -40,9 +40,15 @@
 <script lang="ts">
 import Vue from 'vue';
 import { docsUrl, chUrl, lang } from '../../../config';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['isOpen'],
+	computed: {
+		name() {
+			return getUserName(this.os.i);
+		}
+	},
 	data() {
 		return {
 			hasUnreadNotifications: false,
diff --git a/src/client/app/mobile/views/components/user-card.vue b/src/client/app/mobile/views/components/user-card.vue
index 46fa3b473..e8698a62f 100644
--- a/src/client/app/mobile/views/components/user-card.vue
+++ b/src/client/app/mobile/views/components/user-card.vue
@@ -5,7 +5,7 @@
 			<img :src="`${user.avatarUrl}?thumbnail&size=200`" alt="avatar"/>
 		</a>
 	</header>
-	<a class="name" :href="`/@${acct}`" target="_blank">{{ user.name }}</a>
+	<a class="name" :href="`/@${acct}`" target="_blank">{{ name }}</a>
 	<p class="username">@{{ acct }}</p>
 	<mk-follow-button :user="user"/>
 </div>
@@ -14,12 +14,16 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['user'],
 	computed: {
 		acct() {
 			return getAcct(this.user);
+		},
+		name() {
+			return getUserName(this.user);
 		}
 	}
 });
diff --git a/src/client/app/mobile/views/components/user-preview.vue b/src/client/app/mobile/views/components/user-preview.vue
index 00f87e554..72a6bcf8a 100644
--- a/src/client/app/mobile/views/components/user-preview.vue
+++ b/src/client/app/mobile/views/components/user-preview.vue
@@ -5,7 +5,7 @@
 	</router-link>
 	<div class="main">
 		<header>
-			<router-link class="name" :to="`/@${acct}`">{{ user.name }}</router-link>
+			<router-link class="name" :to="`/@${acct}`">{{ name }}</router-link>
 			<span class="username">@{{ acct }}</span>
 		</header>
 		<div class="body">
@@ -18,12 +18,16 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../acct/render';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['user'],
 	computed: {
 		acct() {
 			return getAcct(this.user);
+		},
+		name() {
+			return getUserName(this.user);
 		}
 	}
 });
diff --git a/src/client/app/mobile/views/pages/followers.vue b/src/client/app/mobile/views/pages/followers.vue
index d2e6a9aea..f4225d556 100644
--- a/src/client/app/mobile/views/pages/followers.vue
+++ b/src/client/app/mobile/views/pages/followers.vue
@@ -2,7 +2,7 @@
 <mk-ui>
 	<template slot="header" v-if="!fetching">
 		<img :src="`${user.avatarUrl}?thumbnail&size=64`" alt="">
-		{{ '%i18n:mobile.tags.mk-user-followers-page.followers-of%'.replace('{}', user.name) }}
+		{{ '%i18n:mobile.tags.mk-user-followers-page.followers-of%'.replace('{}', name) }}
 	</template>
 	<mk-users-list
 		v-if="!fetching"
@@ -20,6 +20,7 @@
 import Vue from 'vue';
 import Progress from '../../../common/scripts/loading';
 import parseAcct from '../../../../../acct/parse';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	data() {
@@ -28,6 +29,11 @@ export default Vue.extend({
 			user: null
 		};
 	},
+	computed: {
+		name() {
+			return getUserName(this.user);
+		}
+	},
 	watch: {
 		$route: 'fetch'
 	},
@@ -46,7 +52,7 @@ export default Vue.extend({
 				this.user = user;
 				this.fetching = false;
 
-				document.title = '%i18n:mobile.tags.mk-user-followers-page.followers-of%'.replace('{}', user.name) + ' | Misskey';
+				document.title = '%i18n:mobile.tags.mk-user-followers-page.followers-of%'.replace('{}', this.name) + ' | Misskey';
 			});
 		},
 		onLoaded() {
diff --git a/src/client/app/mobile/views/pages/following.vue b/src/client/app/mobile/views/pages/following.vue
index 3690536cf..cc2442e47 100644
--- a/src/client/app/mobile/views/pages/following.vue
+++ b/src/client/app/mobile/views/pages/following.vue
@@ -2,7 +2,7 @@
 <mk-ui>
 	<template slot="header" v-if="!fetching">
 		<img :src="`${user.avatarUrl}?thumbnail&size=64`" alt="">
-		{{ '%i18n:mobile.tags.mk-user-following-page.following-of%'.replace('{}', user.name) }}
+		{{ '%i18n:mobile.tags.mk-user-following-page.following-of%'.replace('{}', name) }}
 	</template>
 	<mk-users-list
 		v-if="!fetching"
@@ -20,6 +20,7 @@
 import Vue from 'vue';
 import Progress from '../../../common/scripts/loading';
 import parseAcct from '../../../../../acct/parse';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	data() {
@@ -28,6 +29,11 @@ export default Vue.extend({
 			user: null
 		};
 	},
+	computed: {
+		name() {
+			return getUserName(this.user);
+		}
+	},
 	watch: {
 		$route: 'fetch'
 	},
@@ -46,7 +52,7 @@ export default Vue.extend({
 				this.user = user;
 				this.fetching = false;
 
-				document.title = '%i18n:mobile.tags.mk-user-followers-page.followers-of%'.replace('{}', user.name) + ' | Misskey';
+				document.title = '%i18n:mobile.tags.mk-user-followers-page.followers-of%'.replace('{}', this.name) + ' | Misskey';
 			});
 		},
 		onLoaded() {
diff --git a/src/client/app/mobile/views/pages/messaging-room.vue b/src/client/app/mobile/views/pages/messaging-room.vue
index 172666eea..ae6662dc0 100644
--- a/src/client/app/mobile/views/pages/messaging-room.vue
+++ b/src/client/app/mobile/views/pages/messaging-room.vue
@@ -1,7 +1,7 @@
 <template>
 <mk-ui>
 	<span slot="header">
-		<template v-if="user">%fa:R comments%{{ user.name }}</template>
+		<template v-if="user">%fa:R comments%{{ name }}</template>
 		<template v-else><mk-ellipsis/></template>
 	</span>
 	<mk-messaging-room v-if="!fetching" :user="user" :is-naked="true"/>
@@ -11,6 +11,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import parseAcct from '../../../../../acct/parse';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	data() {
@@ -19,6 +20,11 @@ export default Vue.extend({
 			user: null
 		};
 	},
+	computed: {
+		name() {
+			return getUserName(this.user);
+		}
+	},
 	watch: {
 		$route: 'fetch'
 	},
@@ -33,7 +39,7 @@ export default Vue.extend({
 				this.user = user;
 				this.fetching = false;
 
-				document.title = `%i18n:mobile.tags.mk-messaging-room-page.message%: ${user.name} | Misskey`;
+				document.title = `%i18n:mobile.tags.mk-messaging-room-page.message%: ${this.name} | Misskey`;
 			});
 		}
 	}
diff --git a/src/client/app/mobile/views/pages/profile-setting.vue b/src/client/app/mobile/views/pages/profile-setting.vue
index 15f9bc9b6..4a560c027 100644
--- a/src/client/app/mobile/views/pages/profile-setting.vue
+++ b/src/client/app/mobile/views/pages/profile-setting.vue
@@ -52,7 +52,7 @@ export default Vue.extend({
 		};
 	},
 	created() {
-		this.name = (this as any).os.i.name;
+		this.name = (this as any).os.i.name || '';
 		this.location = (this as any).os.i.account.profile.location;
 		this.description = (this as any).os.i.description;
 		this.birthday = (this as any).os.i.account.profile.birthday;
@@ -94,7 +94,7 @@ export default Vue.extend({
 			this.saving = true;
 
 			(this as any).api('i/update', {
-				name: this.name,
+				name: this.name || null,
 				location: this.location || null,
 				description: this.description || null,
 				birthday: this.birthday || null
diff --git a/src/client/app/mobile/views/pages/settings.vue b/src/client/app/mobile/views/pages/settings.vue
index a945a21c5..58a9d4e37 100644
--- a/src/client/app/mobile/views/pages/settings.vue
+++ b/src/client/app/mobile/views/pages/settings.vue
@@ -2,7 +2,7 @@
 <mk-ui>
 	<span slot="header">%fa:cog%%i18n:mobile.tags.mk-settings-page.settings%</span>
 	<div :class="$style.content">
-		<p v-html="'%i18n:mobile.tags.mk-settings.signed-in-as%'.replace('{}', '<b>' + os.i.name + '</b>')"></p>
+		<p v-html="'%i18n:mobile.tags.mk-settings.signed-in-as%'.replace('{}', '<b>' + name + '</b>')"></p>
 		<ul>
 			<li><router-link to="./settings/profile">%fa:user%%i18n:mobile.tags.mk-settings-page.profile%%fa:angle-right%</router-link></li>
 			<li><router-link to="./settings/authorized-apps">%fa:puzzle-piece%%i18n:mobile.tags.mk-settings-page.applications%%fa:angle-right%</router-link></li>
@@ -20,6 +20,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import { version, codename } from '../../../config';
+import getUserName from '../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	data() {
@@ -28,6 +29,11 @@ export default Vue.extend({
 			codename
 		};
 	},
+	computed: {
+		name() {
+			return getUserName(this.os.i);
+		}
+	},
 	mounted() {
 		document.title = 'Misskey | %i18n:mobile.tags.mk-settings-page.settings%';
 		document.documentElement.style.background = '#313a42';
diff --git a/src/client/app/mobile/views/pages/user.vue b/src/client/app/mobile/views/pages/user.vue
index be696484b..3b7b4d6c2 100644
--- a/src/client/app/mobile/views/pages/user.vue
+++ b/src/client/app/mobile/views/pages/user.vue
@@ -1,6 +1,6 @@
 <template>
 <mk-ui>
-	<span slot="header" v-if="!fetching">%fa:user% {{ user.name }}</span>
+	<span slot="header" v-if="!fetching">%fa:user% {{ user }}</span>
 	<main v-if="!fetching">
 		<header>
 			<div class="banner" :style="user.bannerUrl ? `background-image: url(${user.bannerUrl}?thumbnail&size=1024)` : ''"></div>
@@ -12,7 +12,7 @@
 					<mk-follow-button v-if="os.isSignedIn && os.i.id != user.id" :user="user"/>
 				</div>
 				<div class="title">
-					<h1>{{ user.name }}</h1>
+					<h1>{{ user }}</h1>
 					<span class="username">@{{ acct }}</span>
 					<span class="followed" v-if="user.isFollowed">%i18n:mobile.tags.mk-user.follows-you%</span>
 				</div>
@@ -61,7 +61,7 @@
 import Vue from 'vue';
 import * as age from 's-age';
 import getAcct from '../../../../../acct/render';
-import getAcct from '../../../../../acct/parse';
+import getUserName from '../../../../../renderers/get-user-name';
 import Progress from '../../../common/scripts/loading';
 import XHome from './user/home.vue';
 
@@ -82,6 +82,9 @@ export default Vue.extend({
 		},
 		age(): number {
 			return age(this.user.account.profile.birthday);
+		},
+		name() {
+			return getUserName(this.user);
 		}
 	},
 	watch: {
@@ -102,7 +105,7 @@ export default Vue.extend({
 				this.fetching = false;
 
 				Progress.done();
-				document.title = user.name + ' | Misskey';
+				document.title = this.name + ' | Misskey';
 			});
 		}
 	}
diff --git a/src/client/app/mobile/views/pages/user/home.followers-you-know.vue b/src/client/app/mobile/views/pages/user/home.followers-you-know.vue
index ffdd9f178..1b128e2f2 100644
--- a/src/client/app/mobile/views/pages/user/home.followers-you-know.vue
+++ b/src/client/app/mobile/views/pages/user/home.followers-you-know.vue
@@ -3,7 +3,7 @@
 	<p class="initializing" v-if="fetching">%fa:spinner .pulse .fw%%i18n:mobile.tags.mk-user-overview-followers-you-know.loading%<mk-ellipsis/></p>
 	<div v-if="!fetching && users.length > 0">
 		<a v-for="user in users" :key="user.id" :href="`/@${getAcct(user)}`">
-			<img :src="`${user.avatarUrl}?thumbnail&size=64`" :alt="user.name"/>
+			<img :src="`${user.avatarUrl}?thumbnail&size=64`" :alt="getUserName(user)"/>
 		</a>
 	</div>
 	<p class="empty" v-if="!fetching && users.length == 0">%i18n:mobile.tags.mk-user-overview-followers-you-know.no-users%</p>
@@ -13,6 +13,7 @@
 <script lang="ts">
 import Vue from 'vue';
 import getAcct from '../../../../../../acct/render';
+import getUserName from '../../../../../../renderers/get-user-name';
 
 export default Vue.extend({
 	props: ['user'],
@@ -22,6 +23,11 @@ export default Vue.extend({
 			users: []
 		};
 	},
+	computed: {
+		name() {
+			return getUserName(this.user);
+		}
+	},
 	methods: {
 		getAcct
 	},
diff --git a/src/client/app/mobile/views/widgets/profile.vue b/src/client/app/mobile/views/widgets/profile.vue
index f1d283e45..bd257a3ff 100644
--- a/src/client/app/mobile/views/widgets/profile.vue
+++ b/src/client/app/mobile/views/widgets/profile.vue
@@ -8,15 +8,23 @@
 			:src="`${os.i.avatarUrl}?thumbnail&size=96`"
 			alt="avatar"
 		/>
-		<router-link :class="$style.name" :to="`/@${os.i.username}`">{{ os.i.name }}</router-link>
+		<router-link :class="$style.name" :to="`/@${os.i.username}`">{{ name }}</router-link>
 	</mk-widget-container>
 </div>
 </template>
 
 <script lang="ts">
 import define from '../../../common/define-widget';
+import getUserName from '../../../../../renderers/get-user-name';
+
 export default define({
 	name: 'profile'
+}).extend({
+	computed: {
+		name() {
+			return getUserName(this.os.i);
+		}
+	}
 });
 </script>
 
diff --git a/src/models/user.ts b/src/models/user.ts
index f817c33aa..92091c687 100644
--- a/src/models/user.ts
+++ b/src/models/user.ts
@@ -21,7 +21,7 @@ type IUserBase = {
 	deletedAt: Date;
 	followersCount: number;
 	followingCount: number;
-	name: string;
+	name?: string;
 	postsCount: number;
 	driveCapacity: number;
 	username: string;
@@ -99,8 +99,8 @@ export function validatePassword(password: string): boolean {
 	return typeof password == 'string' && password != '';
 }
 
-export function isValidName(name: string): boolean {
-	return typeof name == 'string' && name.length < 30 && name.trim() != '';
+export function isValidName(name?: string): boolean {
+	return name === null || (typeof name == 'string' && name.length < 30 && name.trim() != '');
 }
 
 export function isValidDescription(description: string): boolean {
diff --git a/src/othello/ai/back.ts b/src/othello/ai/back.ts
index d6704b175..4d06ed956 100644
--- a/src/othello/ai/back.ts
+++ b/src/othello/ai/back.ts
@@ -9,6 +9,7 @@
 import * as request from 'request-promise-native';
 import Othello, { Color } from '../core';
 import conf from '../../config';
+import getUserName from '../../renderers/get-user-name';
 
 let game;
 let form;
@@ -47,8 +48,8 @@ process.on('message', async msg => {
 		const user = game.user1Id == id ? game.user2 : game.user1;
 		const isSettai = form[0].value === 0;
 		const text = isSettai
-			? `?[${user.name}](${conf.url}/@${user.username})さんの接待を始めました！`
-			: `対局を?[${user.name}](${conf.url}/@${user.username})さんと始めました！ (強さ${form[0].value})`;
+			? `?[${getUserName(user)}](${conf.url}/@${user.username})さんの接待を始めました！`
+			: `対局を?[${getUserName(user)}](${conf.url}/@${user.username})さんと始めました！ (強さ${form[0].value})`;
 
 		const res = await request.post(`${conf.api_url}/posts/create`, {
 			json: { i,
@@ -72,15 +73,15 @@ process.on('message', async msg => {
 		const isSettai = form[0].value === 0;
 		const text = isSettai
 			? msg.body.winnerId === null
-				? `?[${user.name}](${conf.url}/@${user.username})さんに接待で引き分けました...`
+				? `?[${getUserName(user)}](${conf.url}/@${user.username})さんに接待で引き分けました...`
 				: msg.body.winnerId == id
-					? `?[${user.name}](${conf.url}/@${user.username})さんに接待で勝ってしまいました...`
-					: `?[${user.name}](${conf.url}/@${user.username})さんに接待で負けてあげました♪`
+					? `?[${getUserName(user)}](${conf.url}/@${user.username})さんに接待で勝ってしまいました...`
+					: `?[${getUserName(user)}](${conf.url}/@${user.username})さんに接待で負けてあげました♪`
 			: msg.body.winnerId === null
-				? `?[${user.name}](${conf.url}/@${user.username})さんと引き分けました～`
+				? `?[${getUserName(user)}](${conf.url}/@${user.username})さんと引き分けました～`
 				: msg.body.winnerId == id
-					? `?[${user.name}](${conf.url}/@${user.username})さんに勝ちました♪`
-					: `?[${user.name}](${conf.url}/@${user.username})さんに負けました...`;
+					? `?[${getUserName(user)}](${conf.url}/@${user.username})さんに勝ちました♪`
+					: `?[${getUserName(user)}](${conf.url}/@${user.username})さんに負けました...`;
 
 		await request.post(`${conf.api_url}/posts/create`, {
 			json: { i,
diff --git a/src/renderers/get-notification-summary.ts b/src/renderers/get-notification-summary.ts
index 03db722c8..f5e38faf9 100644
--- a/src/renderers/get-notification-summary.ts
+++ b/src/renderers/get-notification-summary.ts
@@ -1,3 +1,4 @@
+import getUserName from '../renderers/get-user-name';
 import getPostSummary from './get-post-summary';
 import getReactionEmoji from './get-reaction-emoji';
 
@@ -8,19 +9,19 @@ import getReactionEmoji from './get-reaction-emoji';
 export default function(notification: any): string {
 	switch (notification.type) {
 		case 'follow':
-			return `${notification.user.name}にフォローされました`;
+			return `${getUserName(notification.user)}にフォローされました`;
 		case 'mention':
-			return `言及されました:\n${notification.user.name}「${getPostSummary(notification.post)}」`;
+			return `言及されました:\n${getUserName(notification.user)}「${getPostSummary(notification.post)}」`;
 		case 'reply':
-			return `返信されました:\n${notification.user.name}「${getPostSummary(notification.post)}」`;
+			return `返信されました:\n${getUserName(notification.user)}「${getPostSummary(notification.post)}」`;
 		case 'repost':
-			return `Repostされました:\n${notification.user.name}「${getPostSummary(notification.post)}」`;
+			return `Repostされました:\n${getUserName(notification.user)}「${getPostSummary(notification.post)}」`;
 		case 'quote':
-			return `引用されました:\n${notification.user.name}「${getPostSummary(notification.post)}」`;
+			return `引用されました:\n${getUserName(notification.user)}「${getPostSummary(notification.post)}」`;
 		case 'reaction':
-			return `リアクションされました:\n${notification.user.name} <${getReactionEmoji(notification.reaction)}>「${getPostSummary(notification.post)}」`;
+			return `リアクションされました:\n${getUserName(notification.user)} <${getReactionEmoji(notification.reaction)}>「${getPostSummary(notification.post)}」`;
 		case 'poll_vote':
-			return `投票されました:\n${notification.user.name}「${getPostSummary(notification.post)}」`;
+			return `投票されました:\n${getUserName(notification.user)}「${getPostSummary(notification.post)}」`;
 		default:
 			return `<不明な通知タイプ: ${notification.type}>`;
 	}
diff --git a/src/renderers/get-user-summary.ts b/src/renderers/get-user-summary.ts
index 208987113..d002933b6 100644
--- a/src/renderers/get-user-summary.ts
+++ b/src/renderers/get-user-summary.ts
@@ -1,12 +1,13 @@
 import { IUser, isLocalUser } from '../models/user';
 import getAcct from '../acct/render';
+import getUserName from './get-user-name';
 
 /**
  * ユーザーを表す文字列を取得します。
  * @param user ユーザー
  */
 export default function(user: IUser): string {
-	let string = `${user.name} (@${getAcct(user)})\n` +
+	let string = `${getUserName(user)} (@${getAcct(user)})\n` +
 		`${user.postsCount}投稿、${user.followingCount}フォロー、${user.followersCount}フォロワー\n`;
 
 	if (isLocalUser(user)) {
diff --git a/src/server/api/bot/core.ts b/src/server/api/bot/core.ts
index 7e80f31e5..a44aa9d7b 100644
--- a/src/server/api/bot/core.ts
+++ b/src/server/api/bot/core.ts
@@ -4,6 +4,7 @@ import * as bcrypt from 'bcryptjs';
 import User, { IUser, init as initUser, ILocalUser } from '../../../models/user';
 
 import getPostSummary from '../../../renderers/get-post-summary';
+import getUserName from '../../../renderers/get-user-name';
 import getUserSummary from '../../../renderers/get-user-summary';
 import parseAcct from '../../../acct/parse';
 import getNotificationSummary from '../../../renderers/get-notification-summary';
@@ -90,7 +91,7 @@ export default class BotCore extends EventEmitter {
 					'タイムラインや通知を見た後、「次」というとさらに遡ることができます。';
 
 			case 'me':
-				return this.user ? `${this.user.name}としてサインインしています。\n\n${getUserSummary(this.user)}` : 'サインインしていません';
+				return this.user ? `${getUserName(this.user)}としてサインインしています。\n\n${getUserSummary(this.user)}` : 'サインインしていません';
 
 			case 'login':
 			case 'signin':
@@ -230,7 +231,7 @@ class SigninContext extends Context {
 			if (same) {
 				this.bot.signin(this.temporaryUser);
 				this.bot.clearContext();
-				return `${this.temporaryUser.name}さん、おかえりなさい！`;
+				return `${getUserName(this.temporaryUser)}さん、おかえりなさい！`;
 			} else {
 				return `パスワードが違います... もう一度教えてください:`;
 			}
@@ -305,7 +306,7 @@ class TlContext extends Context {
 			this.emit('updated');
 
 			const text = tl
-				.map(post => `${post.user.name}\n「${getPostSummary(post)}」`)
+				.map(post => `${getUserName(post.user)}\n「${getPostSummary(post)}」`)
 				.join('\n-----\n');
 
 			return text;
diff --git a/src/server/api/bot/interfaces/line.ts b/src/server/api/bot/interfaces/line.ts
index 7847cbdea..1191aaf39 100644
--- a/src/server/api/bot/interfaces/line.ts
+++ b/src/server/api/bot/interfaces/line.ts
@@ -10,6 +10,7 @@ import prominence = require('prominence');
 import getAcct from '../../../../acct/render';
 import parseAcct from '../../../../acct/parse';
 import getPostSummary from '../../../../renderers/get-post-summary';
+import getUserName from '../../../../renderers/get-user-name';
 
 const redis = prominence(_redis);
 
@@ -131,7 +132,7 @@ class LineBot extends BotCore {
 			template: {
 				type: 'buttons',
 				thumbnailImageUrl: `${user.avatarUrl}?thumbnail&size=1024`,
-				title: `${user.name} (@${acct})`,
+				title: `${getUserName(user)} (@${acct})`,
 				text: user.description || '(no description)',
 				actions: actions
 			}
@@ -146,7 +147,7 @@ class LineBot extends BotCore {
 			limit: 5
 		}, this.user);
 
-		const text = `${tl[0].user.name}さんのタイムラインはこちらです:\n\n` + tl
+		const text = `${getUserName(tl[0].user)}さんのタイムラインはこちらです:\n\n` + tl
 			.map(post => getPostSummary(post))
 			.join('\n-----\n');