diff --git a/packages/frontend/src/boot/common.ts b/packages/frontend/src/boot/common.ts
index 90ae49ee59..bfe5c4f5f7 100644
--- a/packages/frontend/src/boot/common.ts
+++ b/packages/frontend/src/boot/common.ts
@@ -15,7 +15,7 @@ import { updateI18n, i18n } from '@/i18n.js';
 import { $i, refreshAccount, login } from '@/account.js';
 import { defaultStore, ColdDeviceStorage } from '@/store.js';
 import { fetchInstance, instance } from '@/instance.js';
-import { deviceKind } from '@/scripts/device-kind.js';
+import { deviceKind, updateDeviceKind } from '@/scripts/device-kind.js';
 import { reloadChannel } from '@/scripts/unison-reload.js';
 import { getUrlWithoutLoginId } from '@/scripts/login-id.js';
 import { getAccountFromId } from '@/scripts/get-account-from-id.js';
@@ -185,6 +185,10 @@ export async function common(createVue: () => App<Element>) {
 		}
 	});
 
+	watch(defaultStore.reactiveState.overridedDeviceKind, (kind) => {
+		updateDeviceKind(kind);
+	}, { immediate: true });
+
 	watch(defaultStore.reactiveState.useBlurEffectForModal, v => {
 		document.documentElement.style.setProperty('--MI-modalBgFilter', v ? 'blur(4px)' : 'none');
 	}, { immediate: true });
diff --git a/packages/frontend/src/scripts/device-kind.ts b/packages/frontend/src/scripts/device-kind.ts
index 095f55d9ce..7aadb617ca 100644
--- a/packages/frontend/src/scripts/device-kind.ts
+++ b/packages/frontend/src/scripts/device-kind.ts
@@ -3,15 +3,22 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { defaultStore } from '@/store.js';
-
-await defaultStore.ready;
+export type DeviceKind = 'smartphone' | 'tablet' | 'desktop';
 
 const ua = navigator.userAgent.toLowerCase();
 const isTablet = /ipad/.test(ua) || (/mobile|iphone|android/.test(ua) && window.innerWidth > 700);
 const isSmartphone = !isTablet && /mobile|iphone|android/.test(ua);
 
-export const deviceKind: 'smartphone' | 'tablet' | 'desktop' = defaultStore.state.overridedDeviceKind ? defaultStore.state.overridedDeviceKind
-	: isSmartphone ? 'smartphone'
-	: isTablet ? 'tablet'
-	: 'desktop';
+export const DEFAULT_DEVICE_KIND: DeviceKind = (
+	isSmartphone
+		? 'smartphone'
+		: isTablet
+			? 'tablet'
+			: 'desktop'
+);
+
+export let deviceKind: DeviceKind = DEFAULT_DEVICE_KIND;
+
+export function updateDeviceKind(kind: DeviceKind | null) {
+	deviceKind = kind ?? DEFAULT_DEVICE_KIND;
+}
diff --git a/packages/frontend/src/store.ts b/packages/frontend/src/store.ts
index 911a463636..1d981e897b 100644
--- a/packages/frontend/src/store.ts
+++ b/packages/frontend/src/store.ts
@@ -8,8 +8,9 @@ import * as Misskey from 'misskey-js';
 import { hemisphere } from '@@/js/intl-const.js';
 import lightTheme from '@@/themes/l-light.json5';
 import darkTheme from '@@/themes/d-green-lime.json5';
-import { miLocalStorage } from './local-storage.js';
 import type { SoundType } from '@/scripts/sound.js';
+import { DEFAULT_DEVICE_KIND, type DeviceKind } from '@/scripts/device-kind.js';
+import { miLocalStorage } from '@/local-storage.js';
 import { Storage } from '@/pizzax.js';
 import type { Ast } from '@syuilo/aiscript';
 
@@ -207,7 +208,7 @@ export const defaultStore = markRaw(new Storage('base', {
 
 	overridedDeviceKind: {
 		where: 'device',
-		default: null as null | 'smartphone' | 'tablet' | 'desktop',
+		default: null as DeviceKind | null,
 	},
 	serverDisconnectedBehavior: {
 		where: 'device',
@@ -263,11 +264,11 @@ export const defaultStore = markRaw(new Storage('base', {
 	},
 	useBlurEffectForModal: {
 		where: 'device',
-		default: !/mobile|iphone|android/.test(navigator.userAgent.toLowerCase()), // 循環参照するのでdevice-kind.tsは参照できない
+		default: DEFAULT_DEVICE_KIND === 'desktop',
 	},
 	useBlurEffect: {
 		where: 'device',
-		default: !/mobile|iphone|android/.test(navigator.userAgent.toLowerCase()), // 循環参照するのでdevice-kind.tsは参照できない
+		default: DEFAULT_DEVICE_KIND === 'desktop',
 	},
 	showFixedPostForm: {
 		where: 'device',