diff --git a/packages/backend/migration/1661376843000-remove-mentioned-remote-users-column.js b/packages/backend/migration/1661376843000-remove-mentioned-remote-users-column.js
new file mode 100644
index 000000000..42d79b5b5
--- /dev/null
+++ b/packages/backend/migration/1661376843000-remove-mentioned-remote-users-column.js
@@ -0,0 +1,12 @@
+export class removeMentionedRemoteUsersColumn1661376843000 {
+	name = 'removeMentionedRemoteUsersColumn1661376843000';
+
+	async up(queryRunner) {
+		await queryRunner.query(`ALTER TABLE "note" DROP COLUMN "mentionedRemoteUsers"`);
+	}
+
+	async down(queryRunner) {
+		await queryRunner.query(`ALTER TABLE "note" ADD "mentionedRemoteUsers" TEXT NOT NULL DEFAULT '[]'::text`);
+		await queryRunner.query(`UPDATE "note" SET "mentionedRemoteUsers" = (SELECT COALESCE(json_agg(row_to_json("data"))::text, '[]') FROM (SELECT "url", "uri", "username", "host" FROM "user" JOIN "user_profile" ON "user"."id" = "user_profile". "userId" WHERE "user"."host" IS NOT NULL AND "user"."id" = ANY("note"."mentions")) AS "data")`);
+	}
+}
diff --git a/packages/backend/src/mfm/to-html.ts b/packages/backend/src/mfm/to-html.ts
index b1429f184..af399e81f 100644
--- a/packages/backend/src/mfm/to-html.ts
+++ b/packages/backend/src/mfm/to-html.ts
@@ -1,17 +1,29 @@
 import { JSDOM } from 'jsdom';
 import * as mfm from 'mfm-js';
 import config from '@/config/index.js';
+import { UserProfiles } from '@/models/index.js';
+import { extractMentions } from '@/misc/extract-mentions.js';
 import { intersperse } from '@/prelude/array.js';
-import { IMentionedRemoteUsers } from '@/models/entities/note.js';
 
-export function toHtml(nodes: mfm.MfmNode[] | null, mentionedRemoteUsers: IMentionedRemoteUsers = []) {
+// Transforms MFM to HTML, given the MFM text and a list of user IDs that are
+// mentioned in the text. If the list of mentions is not given, all mentions
+// from the text will be extracted.
+export async function toHtml(mfmText: string, mentions?: string[]): string | null {
+	const nodes = mfm.parse(mfmText);
 	if (nodes == null) {
 		return null;
 	}
 
-	const { window } = new JSDOM('');
+	const mentionedUsers = await UserProfiles.createQueryBuilder("user_profiles")
+		.leftJoin('user_profile.user', 'user')
+		.select('user.username')
+		.addSelect('user.host')
+		// links should preferably use user friendly urls, only fall back to AP ids
+		.addSelect('COALESCE(user_profile.url, user.uri)', 'url')
+		.where('userId IN (:...ids)', { ids: mentions ?? extractMentions(nodes) })
+		.getManyRaw();
 
-	const doc = window.document;
+	const doc = new JSDOM('').window.document;
 
 	function appendChildren(children: mfm.MfmNode[], targetElement: any): void {
 		if (children) {
@@ -106,18 +118,23 @@ export function toHtml(nodes: mfm.MfmNode[] | null, mentionedRemoteUsers: IMenti
 		},
 
 		mention(node) {
-			// Mastodon microformat: span.h-card > a.u-url.mention
-			const a = doc.createElement('a');
 			const { username, host, acct } = node.props;
-			const remoteUserInfo = mentionedRemoteUsers.find(remoteUser => remoteUser.username === username && remoteUser.host === host);
-			a.href = remoteUserInfo?.url ?? remoteUserInfo?.uri ?? `${config.url}/${acct}`;
-			a.className = 'u-url mention';
-			a.textContent = acct;
+			const userInfo = mentionedUsers.find(user => user.username === username && user.host === host);
+			if (userInfo != null) {
+				// Mastodon microformat: span.h-card > a.u-url.mention
+				const a = doc.createElement('a');
+				a.href = userInfo.url ?? `${config.url}/${acct}`;
+				a.className = 'u-url mention';
+				a.textContent = acct;
 
-			const card = doc.createElement('span');
-			card.className = 'h-card';
-			card.appendChild(a);
-			return card;
+				const card = doc.createElement('span');
+				card.className = 'h-card';
+				card.appendChild(a);
+				return card;
+			} else {
+				// this user does not actually exist
+				return doc.createTextNode(acct);
+			}
 		},
 
 		quote(node) {
diff --git a/packages/backend/src/models/entities/note.ts b/packages/backend/src/models/entities/note.ts
index ee7cbec43..d1e6b9f93 100644
--- a/packages/backend/src/models/entities/note.ts
+++ b/packages/backend/src/models/entities/note.ts
@@ -155,11 +155,6 @@ export class Note {
 	})
 	public mentions: User['id'][];
 
-	@Column('text', {
-		default: '[]',
-	})
-	public mentionedRemoteUsers: string;
-
 	@Column('varchar', {
 		length: 128, array: true, default: '{}',
 	})
@@ -233,10 +228,3 @@ export class Note {
 		}
 	}
 }
-
-export type IMentionedRemoteUsers = {
-	uri: string;
-	url?: string;
-	username: string;
-	host: string;
-}[];
diff --git a/packages/backend/src/remote/activitypub/misc/get-note-html.ts b/packages/backend/src/remote/activitypub/misc/get-note-html.ts
deleted file mode 100644
index 389039ebe..000000000
--- a/packages/backend/src/remote/activitypub/misc/get-note-html.ts
+++ /dev/null
@@ -1,8 +0,0 @@
-import * as mfm from 'mfm-js';
-import { Note } from '@/models/entities/note.js';
-import { toHtml } from '../../../mfm/to-html.js';
-
-export default function(note: Note) {
-	if (!note.text) return '';
-	return toHtml(mfm.parse(note.text), JSON.parse(note.mentionedRemoteUsers));
-}
diff --git a/packages/backend/src/remote/activitypub/renderer/note.ts b/packages/backend/src/remote/activitypub/renderer/note.ts
index f705aabac..1bcb5eae2 100644
--- a/packages/backend/src/remote/activitypub/renderer/note.ts
+++ b/packages/backend/src/remote/activitypub/renderer/note.ts
@@ -1,11 +1,11 @@
 import { In, IsNull } from 'typeorm';
 import config from '@/config/index.js';
-import { Note, IMentionedRemoteUsers } from '@/models/entities/note.js';
+import { Note } from '@/models/entities/note.js';
 import { DriveFile } from '@/models/entities/drive-file.js';
 import { DriveFiles, Notes, Users, Emojis, Polls } from '@/models/index.js';
 import { Emoji } from '@/models/entities/emoji.js';
 import { Poll } from '@/models/entities/poll.js';
-import toHtml from '../misc/get-note-html.js';
+import { toHtml } from '@/mfm/to-html.js';
 import renderEmoji from './emoji.js';
 import renderMention from './mention.js';
 import renderHashtag from './hashtag.js';
@@ -55,28 +55,31 @@ export default async function renderNote(note: Note, dive = true, isTalk = false
 
 	const attributedTo = `${config.url}/users/${note.userId}`;
 
-	const mentions = (JSON.parse(note.mentionedRemoteUsers) as IMentionedRemoteUsers).map(x => x.uri);
+	const mentionedUsers = note.mentions.length > 0 ? await Users.findBy({
+		id: In(note.mentions),
+	}) : [];
+
+	const mentionUris = mentionedUsers
+		// only remote users
+		.filter(user => Users.isRemoteUser(user))
+		.map(user => user.uri);
 
 	let to: string[] = [];
 	let cc: string[] = [];
 
 	if (note.visibility === 'public') {
 		to = ['https://www.w3.org/ns/activitystreams#Public'];
-		cc = [`${attributedTo}/followers`].concat(mentions);
+		cc = [`${attributedTo}/followers`].concat(mentionUris);
 	} else if (note.visibility === 'home') {
 		to = [`${attributedTo}/followers`];
-		cc = ['https://www.w3.org/ns/activitystreams#Public'].concat(mentions);
+		cc = ['https://www.w3.org/ns/activitystreams#Public'].concat(mentionUris);
 	} else if (note.visibility === 'followers') {
 		to = [`${attributedTo}/followers`];
-		cc = mentions;
+		cc = mentionUris;
 	} else {
-		to = mentions;
+		to = mentionUris;
 	}
 
-	const mentionedUsers = note.mentions.length > 0 ? await Users.findBy({
-		id: In(note.mentions),
-	}) : [];
-
 	const hashtagTags = (note.tags || []).map(tag => renderHashtag(tag));
 	const mentionTags = mentionedUsers.map(u => renderMention(u));
 
@@ -97,9 +100,7 @@ export default async function renderNote(note: Note, dive = true, isTalk = false
 
 	const summary = note.cw === '' ? String.fromCharCode(0x200B) : note.cw;
 
-	const content = toHtml(Object.assign({}, note, {
-		text: apText,
-	}));
+	const content = await toHtml(apText, note.mentions);
 
 	const emojis = await getEmojis(note.emojis);
 	const apemojis = emojis.map(emoji => renderEmoji(emoji));
@@ -112,7 +113,7 @@ export default async function renderNote(note: Note, dive = true, isTalk = false
 
 	const asPoll = poll ? {
 		type: 'Question',
-		content: toHtml(Object.assign({}, note, { text })),
+		content: await toHtml(text, note.mentions),
 		[poll.expiresAt && poll.expiresAt < new Date() ? 'closed' : 'endTime']: poll.expiresAt,
 		[poll.multiple ? 'anyOf' : 'oneOf']: poll.choices.map((text, i) => ({
 			type: 'Note',
diff --git a/packages/backend/src/remote/activitypub/renderer/person.ts b/packages/backend/src/remote/activitypub/renderer/person.ts
index 213741143..7de957882 100644
--- a/packages/backend/src/remote/activitypub/renderer/person.ts
+++ b/packages/backend/src/remote/activitypub/renderer/person.ts
@@ -1,5 +1,4 @@
 import { URL } from 'node:url';
-import * as mfm from 'mfm-js';
 import config from '@/config/index.js';
 import { ILocalUser } from '@/models/entities/user.js';
 import { toHtml } from '@/mfm/to-html.js';
@@ -66,7 +65,7 @@ export async function renderPerson(user: ILocalUser) {
 		url: `${config.url}/@${user.username}`,
 		preferredUsername: user.username,
 		name: user.name,
-		summary: profile.description ? toHtml(mfm.parse(profile.description)) : null,
+		summary: profile.description ? await toHtml(profile.description) : null,
 		icon: avatar ? renderImage(avatar) : null,
 		image: banner ? renderImage(banner) : null,
 		tag,
diff --git a/packages/backend/src/services/messages/create.ts b/packages/backend/src/services/messages/create.ts
index b5892a891..4a0ea53a8 100644
--- a/packages/backend/src/services/messages/create.ts
+++ b/packages/backend/src/services/messages/create.ts
@@ -93,11 +93,6 @@ export async function createMessage(user: { id: User['id']; host: User['host'];
 			userId: message.userId,
 			visibility: 'specified',
 			mentions: [ recipientUser.id ],
-			mentionedRemoteUsers: JSON.stringify([ recipientUser ].map(u => ({
-				uri: u.uri,
-				username: u.username,
-				host: u.host,
-			}))),
 		} as Note;
 
 		const activity = renderActivity(renderCreate(await renderNote(note, false, true), note));
diff --git a/packages/backend/src/services/note/create.ts b/packages/backend/src/services/note/create.ts
index 84bfa89eb..9761de0e5 100644
--- a/packages/backend/src/services/note/create.ts
+++ b/packages/backend/src/services/note/create.ts
@@ -15,7 +15,7 @@ import { insertNoteUnread } from '@/services/note/unread.js';
 import { extractMentions } from '@/misc/extract-mentions.js';
 import { extractCustomEmojisFromMfm } from '@/misc/extract-custom-emojis-from-mfm.js';
 import { extractHashtags } from '@/misc/extract-hashtags.js';
-import { Note, IMentionedRemoteUsers } from '@/models/entities/note.js';
+import { Note } from '@/models/entities/note.js';
 import { Mutings, Users, NoteWatchings, Notes, Instances, UserProfiles, MutedNotes, Channels, ChannelFollowings, NoteThreadMutings } from '@/models/index.js';
 import { DriveFile } from '@/models/entities/drive-file.js';
 import { App } from '@/models/entities/app.js';
@@ -537,16 +537,6 @@ async function insertNote(user: { id: User['id']; host: User['host']; }, data: O
 	// Append mentions data
 	if (mentionedUsers.length > 0) {
 		insert.mentions = mentionedUsers.map(u => u.id);
-		const profiles = await UserProfiles.findBy({ userId: In(insert.mentions) });
-		insert.mentionedRemoteUsers = JSON.stringify(mentionedUsers.filter(u => Users.isRemoteUser(u)).map(u => {
-			const profile = profiles.find(p => p.userId === u.id);
-			return {
-				uri: u.uri,
-				url: profile?.url,
-				username: u.username,
-				host: u.host,
-			} as IMentionedRemoteUsers[0];
-		}));
 	}
 
 	// 投稿を作成
diff --git a/packages/backend/src/services/note/delete.ts b/packages/backend/src/services/note/delete.ts
index fc156b584..61b75c963 100644
--- a/packages/backend/src/services/note/delete.ts
+++ b/packages/backend/src/services/note/delete.ts
@@ -1,4 +1,4 @@
-import { Brackets, In } from 'typeorm';
+import { Brackets, In, IsNull, Not } from 'typeorm';
 import { publishNoteStream } from '@/services/stream.js';
 import renderDelete from '@/remote/activitypub/renderer/delete.js';
 import renderAnnounce from '@/remote/activitypub/renderer/announce.js';
@@ -7,7 +7,7 @@ import { renderActivity } from '@/remote/activitypub/renderer/index.js';
 import renderTombstone from '@/remote/activitypub/renderer/tombstone.js';
 import config from '@/config/index.js';
 import { User, ILocalUser, IRemoteUser } from '@/models/entities/user.js';
-import { Note, IMentionedRemoteUsers } from '@/models/entities/note.js';
+import { Note } from '@/models/entities/note.js';
 import { Notes, Users, Instances } from '@/models/index.js';
 import { notesChart, perUserNotesChart, instanceChart } from '@/services/chart/index.js';
 import { deliverToFollowers, deliverToUser } from '@/remote/activitypub/deliver-manager.js';
@@ -109,11 +109,12 @@ async function getMentionedRemoteUsers(note: Note): Promise<IRemoteUser[]> {
 	const where = [] as any[];
 
 	// mention / reply / dm
-	const uris = (JSON.parse(note.mentionedRemoteUsers) as IMentionedRemoteUsers).map(x => x.uri);
-	if (uris.length > 0) {
-		where.push(
-			{ uri: In(uris) },
-		);
+	if (note.mentions > 0) {
+		where.push({
+			id: In(note.mentions),
+			// only remote users, local users are on the server and do not need to be notified
+			host: Not(IsNull()),
+		});
 	}
 
 	// renote / quote