diff --git a/.config/ci.yml b/.config/ci.yml
index c48fca49b..5fc2c787a 100644
--- a/.config/ci.yml
+++ b/.config/ci.yml
@@ -106,7 +106,7 @@ redis:
 #   ┌───────────────────────────┐
 #───┘ MeiliSearch configuration └─────────────────────────────
 
-# You can set scope to local (default value) or global 
+# You can set scope to local (default value) or global
 # (include notes from remote).
 
 #meilisearch:
@@ -204,7 +204,7 @@ signToActivityPubGet: true
 checkActivityPubGetSignature: false
 
 # For security reasons, uploading attachments from the intranet is prohibited,
-# but exceptions can be made from the following settings. Default value is "undefined". 
+# but exceptions can be made from the following settings. Default value is "undefined".
 # Read changelog to learn more (Improvements of 12.90.0 (2021/09/04)).
 #allowedPrivateNetworks: [
 #  '127.0.0.1/32'
@@ -212,5 +212,9 @@ checkActivityPubGetSignature: false
 
 #customMOTD: ['Hello World', 'The sharks rule all', 'Shonks']
 
+# Prefer these languages for remote notes with language-specific content
+# Must be valid language codes according to BCP 47
+#langPref: ['en', 'ja']
+
 # Upload or download file size limits (bytes)
 #maxFileSize: 262144000
diff --git a/.config/docker_example.yml b/.config/docker_example.yml
index 296237c95..4aa2dc9a1 100644
--- a/.config/docker_example.yml
+++ b/.config/docker_example.yml
@@ -163,7 +163,7 @@ redis:
 #   ┌───────────────────────────┐
 #───┘ MeiliSearch configuration └─────────────────────────────
 
-# You can set scope to local (default value) or global 
+# You can set scope to local (default value) or global
 # (include notes from remote).
 
 #meilisearch:
@@ -261,7 +261,7 @@ signToActivityPubGet: true
 checkActivityPubGetSignature: false
 
 # For security reasons, uploading attachments from the intranet is prohibited,
-# but exceptions can be made from the following settings. Default value is "undefined". 
+# but exceptions can be made from the following settings. Default value is "undefined".
 # Read changelog to learn more (Improvements of 12.90.0 (2021/09/04)).
 #allowedPrivateNetworks: [
 #  '127.0.0.1/32'
@@ -269,5 +269,9 @@ checkActivityPubGetSignature: false
 
 #customMOTD: ['Hello World', 'The sharks rule all', 'Shonks']
 
+# Prefer these languages for remote notes with language-specific content
+# Must be valid language codes according to BCP 47
+#langPref: ['en', 'ja']
+
 # Upload or download file size limits (bytes)
 #maxFileSize: 262144000
diff --git a/.config/example.yml b/.config/example.yml
index c037a280b..9af68272d 100644
--- a/.config/example.yml
+++ b/.config/example.yml
@@ -284,6 +284,10 @@ checkActivityPubGetSignature: false
 
 #customMOTD: ['Hello World', 'The sharks rule all', 'Shonks']
 
+# Prefer these languages for remote notes with language-specific content
+# Must be valid language codes according to BCP 47
+#langPref: ['en', 'ja']
+
 # Upload or download file size limits (bytes)
 #maxFileSize: 262144000
 
diff --git a/packages/backend/src/config.ts b/packages/backend/src/config.ts
index c99bc7ae0..2fa736951 100644
--- a/packages/backend/src/config.ts
+++ b/packages/backend/src/config.ts
@@ -91,6 +91,8 @@ type Source = {
 
 	customMOTD?: string[];
 
+	langPref?: string[];
+
 	signToActivityPubGet?: boolean;
 	checkActivityPubGetSignature?: boolean;
 
@@ -153,6 +155,7 @@ export type Config = {
 	customMOTD: string[] | undefined;
 	signToActivityPubGet: boolean;
 	checkActivityPubGetSignature: boolean | undefined;
+	langPref: string[];
 
 	version: string;
 	publishTarballInsteadOfProvideRepositoryUrl: boolean;
@@ -269,6 +272,7 @@ export function loadConfig(): Config {
 		inboxJobMaxAttempts: config.inboxJobMaxAttempts,
 		proxyRemoteFiles: config.proxyRemoteFiles,
 		customMOTD: config.customMOTD,
+		langPref: config.langPref ?? ['en', 'ja'],
 		signToActivityPubGet: config.signToActivityPubGet ?? true,
 		checkActivityPubGetSignature: config.checkActivityPubGetSignature,
 		mediaProxy: externalMediaProxy ?? internalMediaProxy,
diff --git a/packages/backend/src/core/activitypub/models/ApNoteService.ts b/packages/backend/src/core/activitypub/models/ApNoteService.ts
index 204846f7d..ded331e75 100644
--- a/packages/backend/src/core/activitypub/models/ApNoteService.ts
+++ b/packages/backend/src/core/activitypub/models/ApNoteService.ts
@@ -25,7 +25,7 @@ import { StatusError } from '@/misc/status-error.js';
 import { UtilityService } from '@/core/UtilityService.js';
 import { bindThis } from '@/decorators.js';
 import { checkHttps } from '@/misc/check-https.js';
-import { langmap } from '@/misc/langmap.js';
+import { langs } from '@/misc/langmap.js';
 import { getOneApId, getApId, getOneApHrefNullable, validPost, isEmoji, getApType } from '../type.js';
 import { ApLoggerService } from '../ApLoggerService.js';
 import { ApMfmService } from '../ApMfmService.js';
@@ -241,25 +241,37 @@ export class ApNoteService {
 
 		const cw = note.summary === '' ? null : note.summary;
 
+		let lang: string | null = null;
+		if (note.contentMap != null) {
+			for (const preferredLang of this.config.langPref) {
+				if (note.contentMap[preferredLang]) {
+					lang = preferredLang;
+					break;
+				}
+			}
+
+			if (!lang) lang = Object.keys(note.contentMap)[0];
+			if (!langs.includes(lang)) lang = null;
+		}
+
 		// テキストのパース
 		let text: string | null = null;
 		if (note.source?.mediaType === 'text/x.misskeymarkdown' && typeof note.source.content === 'string') {
 			text = note.source.content;
-		} else if (note.contentMap != null) {
-			const entry = Object.entries(note.contentMap)[0];
-			text = this.apMfmService.htmlToMfm(entry[1], note.tag);
+		} else if (note.contentMap != null && Object.keys(note.contentMap).length !== 0) {
+			let content: string;
+			if (lang) {
+				content = note.contentMap[lang];
+			} else {
+				content = Object.values(note.contentMap)[0];
+			}
+			text = this.apMfmService.htmlToMfm(content, note.tag);
 		} else if (typeof note._misskey_content !== 'undefined') {
 			text = note._misskey_content;
 		} else if (typeof note.content === 'string') {
 			text = this.apMfmService.htmlToMfm(note.content, note.tag);
 		}
 
-		let lang: string | null = null;
-		if (note.contentMap != null) {
-			const key = Object.keys(note.contentMap)[0];
-			lang = Object.keys(langmap).includes(key) ? key : null;
-		}
-
 		// vote
 		if (reply && reply.hasPoll) {
 			const poll = await this.pollsRepository.findOneByOrFail({ noteId: reply.id });
@@ -459,25 +471,37 @@ export class ApNoteService {
 
 		const cw = note.summary === '' ? null : note.summary;
 
+		let lang: string | null = null;
+		if (note.contentMap != null) {
+			for (const preferredLang of this.config.langPref) {
+				if (note.contentMap[preferredLang]) {
+					lang = preferredLang;
+					break;
+				}
+			}
+
+			if (!lang) lang = Object.keys(note.contentMap)[0];
+			if (!langs.includes(lang)) lang = null;
+		}
+
 		// テキストのパース
 		let text: string | null = null;
 		if (note.source?.mediaType === 'text/x.misskeymarkdown' && typeof note.source.content === 'string') {
 			text = note.source.content;
-		} else if (note.contentMap != null) {
-			const entry = Object.entries(note.contentMap)[0];
-			text = this.apMfmService.htmlToMfm(entry[1], note.tag);
+		} else if (note.contentMap != null && Object.keys(note.contentMap).length !== 0) {
+			let content: string;
+			if (lang) {
+				content = note.contentMap[lang];
+			} else {
+				content = Object.values(note.contentMap)[0];
+			}
+			text = this.apMfmService.htmlToMfm(content, note.tag);
 		} else if (typeof note._misskey_content !== 'undefined') {
 			text = note._misskey_content;
 		} else if (typeof note.content === 'string') {
 			text = this.apMfmService.htmlToMfm(note.content, note.tag);
 		}
 
-		let lang: string | null = null;
-		if (note.contentMap != null) {
-			const key = Object.keys(note.contentMap)[0];
-			lang = Object.keys(langmap).includes(key) ? key : null;
-		}
-
 		// vote
 		if (reply && reply.hasPoll) {
 			const poll = await this.pollsRepository.findOneByOrFail({ noteId: reply.id });
diff --git a/packages/backend/src/misc/langmap.ts b/packages/backend/src/misc/langmap.ts
index 6b6e8b5b7..f7e237d30 100644
--- a/packages/backend/src/misc/langmap.ts
+++ b/packages/backend/src/misc/langmap.ts
@@ -385,3 +385,4 @@ export const iso639Regional = {
 };
 
 export const langmap = Object.assign({}, langmapNoRegion, iso639Regional);
+export const langs = Object.keys(langmap);
diff --git a/packages/backend/src/models/json-schema/note.ts b/packages/backend/src/models/json-schema/note.ts
index 766ff411f..5a7a1deda 100644
--- a/packages/backend/src/models/json-schema/note.ts
+++ b/packages/backend/src/models/json-schema/note.ts
@@ -2,7 +2,7 @@
  * SPDX-FileCopyrightText: syuilo and misskey-project
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-import { langmap } from '@/misc/langmap.js';
+import { langs } from '@/misc/langmap.js';
 
 export const packedNoteSchema = {
 	type: 'object',
@@ -29,7 +29,7 @@ export const packedNoteSchema = {
 		},
 		lang: {
 			type: 'string',
-			enum: [...Object.keys(langmap)],
+			enum: langs,
 			nullable: true,
 		},
 		cw: {
diff --git a/packages/backend/src/server/api/endpoints/i/update.ts b/packages/backend/src/server/api/endpoints/i/update.ts
index 2c04b6573..a48c74420 100644
--- a/packages/backend/src/server/api/endpoints/i/update.ts
+++ b/packages/backend/src/server/api/endpoints/i/update.ts
@@ -17,7 +17,7 @@ import { birthdaySchema, listenbrainzSchema, descriptionSchema, locationSchema,
 import type { MiUserProfile } from '@/models/UserProfile.js';
 import { notificationTypes } from '@/types.js';
 import { normalizeForSearch } from '@/misc/normalize-for-search.js';
-import { langmap } from '@/misc/langmap.js';
+import { langs } from '@/misc/langmap.js';
 import { Endpoint } from '@/server/api/endpoint-base.js';
 import { UserEntityService } from '@/core/entities/UserEntityService.js';
 import { GlobalEventService } from '@/core/GlobalEventService.js';
@@ -149,7 +149,7 @@ export const paramDef = {
 		location: { ...locationSchema, nullable: true },
 		birthday: { ...birthdaySchema, nullable: true },
 		listenbrainz: { ...listenbrainzSchema, nullable: true },
-		lang: { type: 'string', enum: [null, ...Object.keys(langmap)] as string[], nullable: true },
+		lang: { type: 'string', enum: [null, ...langs] as string[], nullable: true },
 		avatarId: { type: 'string', format: 'misskey:id', nullable: true },
 		avatarDecorations: { type: 'array', maxItems: 16, items: {
 			type: 'object',
@@ -382,7 +382,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				updates.backgroundUrl = null;
 				updates.backgroundBlurhash = null;
 			}
-			
+
 			if (ps.avatarDecorations) {
 				const decorations = await this.avatarDecorationService.getAll(true);
 				const [myRoles, myPolicies] = await Promise.all([this.roleService.getUserRoles(user.id), this.roleService.getUserPolicies(user.id)]);
diff --git a/packages/backend/src/server/api/endpoints/notes/create.ts b/packages/backend/src/server/api/endpoints/notes/create.ts
index 3c6714235..96ff1de26 100644
--- a/packages/backend/src/server/api/endpoints/notes/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/create.ts
@@ -20,7 +20,7 @@ import { isPureRenote } from '@/misc/is-pure-renote.js';
 import { MetaService } from '@/core/MetaService.js';
 import { UtilityService } from '@/core/UtilityService.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
-import { langmap } from '@/misc/langmap.js';
+import { langs } from '@/misc/langmap.js';
 import { ApiError } from '../../error.js';
 
 export const meta = {
@@ -137,7 +137,7 @@ export const paramDef = {
 		visibleUserIds: { type: 'array', uniqueItems: true, items: {
 			type: 'string', format: 'misskey:id',
 		} },
-		lang: { type: 'string', enum: Object.keys(langmap), nullable: true, maxLength: 10 },
+		lang: { type: 'string', enum: langs, nullable: true, maxLength: 10 },
 		cw: { type: 'string', nullable: true, minLength: 1, maxLength: 500 },
 		localOnly: { type: 'boolean', default: false },
 		reactionAcceptance: { type: 'string', nullable: true, enum: [null, 'likeOnly', 'likeOnlyForRemote', 'nonSensitiveOnly', 'nonSensitiveOnlyForLocalLikeOnlyForRemote'], default: null },
diff --git a/packages/backend/src/server/api/endpoints/notes/edit.ts b/packages/backend/src/server/api/endpoints/notes/edit.ts
index fa2225667..622965239 100644
--- a/packages/backend/src/server/api/endpoints/notes/edit.ts
+++ b/packages/backend/src/server/api/endpoints/notes/edit.ts
@@ -12,7 +12,7 @@ import { NoteEntityService } from '@/core/entities/NoteEntityService.js';
 import { NoteEditService } from '@/core/NoteEditService.js';
 import { DI } from '@/di-symbols.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
-import { langmap } from '@/misc/langmap.js';
+import { langs } from '@/misc/langmap.js';
 import { ApiError } from '../../error.js';
 
 export const meta = {
@@ -165,7 +165,7 @@ export const paramDef = {
 				format: 'misskey:id',
 			},
 		},
-		lang: { type: 'string', enum: Object.keys(langmap), nullable: true, maxLength: 10 },
+		lang: { type: 'string', enum: langs, nullable: true, maxLength: 10 },
 		cw: { type: 'string', nullable: true, minLength: 1, maxLength: 500 },
 		localOnly: { type: 'boolean', default: false },
 		reactionAcceptance: { type: 'string', nullable: true, enum: [null, 'likeOnly', 'likeOnlyForRemote', 'nonSensitiveOnly', 'nonSensitiveOnlyForLocalLikeOnlyForRemote'], default: null },
diff --git a/packages/frontend/src/components/MkPostForm.vue b/packages/frontend/src/components/MkPostForm.vue
index 251493480..18d18ed19 100644
--- a/packages/frontend/src/components/MkPostForm.vue
+++ b/packages/frontend/src/components/MkPostForm.vue
@@ -134,7 +134,7 @@ import { miLocalStorage } from '@/local-storage.js';
 import { claimAchievement } from '@/scripts/achievements.js';
 import { emojiPicker } from '@/scripts/emoji-picker.js';
 import { mfmFunctionPicker } from '@/scripts/mfm-function-picker.js';
-import { langmap } from '@/scripts/langmap.js';
+import { langmap, langs } from '@/scripts/langmap.js';
 import { MenuItem } from '@/types/menu.js';
 
 const $i = signinRequired();
@@ -547,7 +547,6 @@ async function toggleReactionAcceptance() {
 
 function attemptNormalizeLang(lang: string | null) {
 	if (lang == null) return null;
-	const langs = Object.keys(langmap);
 	if (!langs[lang]) lang = lang.split('-')[0];
 	return lang;
 }
@@ -562,8 +561,6 @@ function setLanguage(ev: MouseEvent) {
 		action: () => {},
 	});
 
-	const langs = Object.keys(langmap);
-
 	// Show recently used language first
 	let recentlyUsedLanguagesExist = false;
 	for (const lang of defaultStore.state.recentlyUsedPostLanguages) {
@@ -959,11 +956,10 @@ async function post(ev?: MouseEvent) {
 
 	// update recentlyUsedLanguages
 	if (language.value != null) {
-		const languages = Object.keys(langmap);
 		const maxLength = 6;
 
 		defaultStore.set('recentlyUsedPostLanguages', [language.value].concat(defaultStore.state.recentlyUsedPostLanguages.filter((lang) => {
-			return (lang !== language.value && languages.includes(lang));
+			return (lang !== language.value && langs.includes(lang));
 		})).slice(0, maxLength));
 	}
 }
diff --git a/packages/frontend/src/pages/settings/profile.vue b/packages/frontend/src/pages/settings/profile.vue
index 408cf4ed6..2a55c7093 100644
--- a/packages/frontend/src/pages/settings/profile.vue
+++ b/packages/frontend/src/pages/settings/profile.vue
@@ -45,7 +45,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 	<MkSelect v-model="profile.lang">
 		<template #label>{{ i18n.ts.language }}</template>
-		<option v-for="x in Object.keys(langmap)" :key="x" :value="x">{{ langmap[x].nativeName }}</option>
+		<option v-for="x in langs" :key="x" :value="x">{{ langmap[x].nativeName }}</option>
 	</MkSelect>
 
 	<FormSlot>
@@ -128,7 +128,7 @@ import { selectFile } from '@/scripts/select-file.js';
 import * as os from '@/os.js';
 import { i18n } from '@/i18n.js';
 import { signinRequired } from '@/account.js';
-import { langmap } from '@/scripts/langmap.js';
+import { langmap, langs } from '@/scripts/langmap.js';
 import { definePageMetadata } from '@/scripts/page-metadata.js';
 import { claimAchievement } from '@/scripts/achievements.js';
 import { defaultStore } from '@/store.js';
diff --git a/packages/frontend/src/scripts/langmap.ts b/packages/frontend/src/scripts/langmap.ts
index eb23fe2d7..9415d0293 100644
--- a/packages/frontend/src/scripts/langmap.ts
+++ b/packages/frontend/src/scripts/langmap.ts
@@ -385,3 +385,4 @@ export const iso639Regional = {
 };
 
 export const langmap = Object.assign({}, langmapNoRegion, iso639Regional);
+export const langs = Object.keys(langmap);