diff --git a/packages/client/package.json b/packages/client/package.json
index a8ca3a2f0..8860662cd 100644
--- a/packages/client/package.json
+++ b/packages/client/package.json
@@ -27,7 +27,6 @@
 		"compare-versions": "5.0.1",
 		"cropperjs": "2.0.0-beta",
 		"date-fns": "2.29.3",
-		"deepcopy": "2.1.0",
 		"escape-regexp": "0.0.1",
 		"eventemitter3": "4.0.7",
 		"idb-keyval": "6.2.0",
diff --git a/packages/client/src/init.ts b/packages/client/src/init.ts
index 5af113606..f9e08d79b 100644
--- a/packages/client/src/init.ts
+++ b/packages/client/src/init.ts
@@ -38,7 +38,6 @@ import { reloadChannel } from '@/scripts/unison-reload';
 import { reactionPicker } from '@/scripts/reaction-picker';
 import { getUrlWithoutLoginId } from '@/scripts/login-id';
 import { getAccountFromId } from '@/scripts/get-account-from-id';
-import { deckStore } from './ui/deck/deck-store';
 
 (async () => {
 	console.info(`Misskey v${version}`);
@@ -74,8 +73,6 @@ import { deckStore } from './ui/deck/deck-store';
 		});
 	}
 
-	await defaultStore.ready;
-
 	// タッチデバイスでCSSの:hoverを機能させる
 	document.addEventListener('touchend', () => {}, { passive: true });
 
@@ -191,8 +188,6 @@ import { deckStore } from './ui/deck/deck-store';
 		splash.remove();
 	});
 
-	await deckStore.ready;
-
 	// https://github.com/misskey-dev/misskey/pull/8575#issuecomment-1114239210
 	// なぜかinit.tsの内容が2回実行されることがあるため、mountするdivを1つに制限する
 	const rootEl = (() => {
diff --git a/packages/client/src/pizzax.ts b/packages/client/src/pizzax.ts
index c98de098a..642e1f4f7 100644
--- a/packages/client/src/pizzax.ts
+++ b/packages/client/src/pizzax.ts
@@ -1,12 +1,8 @@
 // PIZZAX --- A lightweight store
 
 import { onUnmounted, Ref, ref, watch } from 'vue';
-import { BroadcastChannel } from 'broadcast-channel';
-import deepcopy from 'deepcopy';
 import { $i } from './account';
 import { api } from './os';
-import { get, set } from './scripts/idb-proxy';
-import { defaultStore } from './store';
 import { stream } from './stream';
 
 type StateDef = Record<string, {
@@ -14,196 +10,119 @@ type StateDef = Record<string, {
 	default: any;
 }>;
 
-type State<T extends StateDef> = { [K in keyof T]: T[K]['default']; };
-type ReactiveState<T extends StateDef> = { [K in keyof T]: Ref<T[K]['default']>; };
-
 type ArrayElement<A> = A extends readonly (infer T)[] ? T : never;
 
-type PizzaxChannelMessage<T extends StateDef> = {
-	where: 'device' | 'deviceAccount';
-	key: keyof T;
-	value: T[keyof T]['default'];
-	userId?: string;
-};
-
 const connection = $i && stream.useChannel('main');
 
 export class Storage<T extends StateDef> {
-	public readonly ready: Promise<void>;
-	public readonly loaded: Promise<void>;
-
 	public readonly key: string;
-	public readonly deviceStateKeyName: `pizzax::${this['key']}`;
-	public readonly deviceAccountStateKeyName: `pizzax::${this['key']}::${string}` | '';
-	public readonly registryCacheKeyName: `pizzax::${this['key']}::cache::${string}` | '';
+	public readonly keyForLocalStorage: string;
 
 	public readonly def: T;
 
 	// TODO: これが実装されたらreadonlyにしたい: https://github.com/microsoft/TypeScript/issues/37487
-	public readonly state: State<T>;
-	public readonly reactiveState: ReactiveState<T>;
-
-	private pizzaxChannel: BroadcastChannel<PizzaxChannelMessage<T>>;
-
-	// 簡易的にキューイングして占有ロックとする
-	private currentIdbJob: Promise<any> = Promise.resolve();
-	private addIdbSetJob<T>(job: () => Promise<T>) {
-		const promise = this.currentIdbJob.then(job, e => {
-			console.error('Pizzax failed to save data to idb!', e);
-			return job();
-		});
-		this.currentIdbJob = promise;
-		return promise;
-	}
+	public readonly state: { [K in keyof T]: T[K]['default'] };
+	public readonly reactiveState: { [K in keyof T]: Ref<T[K]['default']> };
 
 	constructor(key: string, def: T) {
 		this.key = key;
-		this.deviceStateKeyName = `pizzax::${key}`;
-		this.deviceAccountStateKeyName = $i ? `pizzax::${key}::${$i.id}` : '';
-		this.registryCacheKeyName = $i ? `pizzax::${key}::cache::${$i.id}` : '';
+		this.keyForLocalStorage = 'pizzax::' + key;
 		this.def = def;
 
-		this.pizzaxChannel = new BroadcastChannel(`pizzax::${key}`);
+		// TODO: indexedDBにする
+		const deviceState = JSON.parse(localStorage.getItem(this.keyForLocalStorage) || '{}');
+		const deviceAccountState = $i ? JSON.parse(localStorage.getItem(this.keyForLocalStorage + '::' + $i.id) || '{}') : {};
+		const registryCache = $i ? JSON.parse(localStorage.getItem(this.keyForLocalStorage + '::cache::' + $i.id) || '{}') : {};
 
-		this.state = {} as State<T>;
-		this.reactiveState = {} as ReactiveState<T>;
-
-		for (const [k, v] of Object.entries(def) as [keyof T, T[keyof T]['default']][]) {
-			this.state[k] = v.default;
-			this.reactiveState[k] = ref(v.default);
-		}
-	
-		this.ready = this.init();
-		this.loaded = this.ready.then(() => this.load());
-	}
-
-	private async init(): Promise<void> {
-		await this.migrate();
-
-		const deviceState: State<T> = await get(this.deviceStateKeyName) || {};
-		const deviceAccountState = $i ? await get(this.deviceAccountStateKeyName) || {} : {};
-		const registryCache = $i ? await get(this.registryCacheKeyName) || {} : {};
-	
-		for (const [k, v] of Object.entries(this.def) as [keyof T, T[keyof T]['default']][]) {
+		const state = {};
+		const reactiveState = {};
+		for (const [k, v] of Object.entries(def)) {
 			if (v.where === 'device' && Object.prototype.hasOwnProperty.call(deviceState, k)) {
-				this.reactiveState[k].value = this.state[k] = deviceState[k];
+				state[k] = deviceState[k];
 			} else if (v.where === 'account' && $i && Object.prototype.hasOwnProperty.call(registryCache, k)) {
-				this.reactiveState[k].value = this.state[k] = registryCache[k];
+				state[k] = registryCache[k];
 			} else if (v.where === 'deviceAccount' && Object.prototype.hasOwnProperty.call(deviceAccountState, k)) {
-				this.reactiveState[k].value = this.state[k] = deviceAccountState[k];
+				state[k] = deviceAccountState[k];
 			} else {
-				this.reactiveState[k].value = this.state[k] = v.default;
+				state[k] = v.default;
 				if (_DEV_) console.log('Use default value', k, v.default);
 			}
 		}
-
-		this.pizzaxChannel.addEventListener('message', ({ where, key, value, userId }) => {
-			// アカウント変更すればunisonReloadが効くため、このreturnが発火することは
-			// まずないと思うけど一応弾いておく
-			if (where === 'deviceAccount' && !($i && userId !== $i.id)) return;
-			this.reactiveState[key].value = this.state[key] = value;
-		});
-
-		if ($i) {
-			// streamingのuser storage updateイベントを監視して更新
-			connection?.on('registryUpdated', ({ scope, key, value }: { scope?: string[], key: keyof T, value: T[typeof key]['default'] }) => {
-				if (!scope || scope.length !== 2 || scope[0] !== 'client' || scope[1] !== this.key || this.state[key] === value) return;
-
-				this.reactiveState[key].value = this.state[key] = value;
+		for (const [k, v] of Object.entries(state)) {
+			reactiveState[k] = ref(v);
+		}
+		this.state = state as any;
+		this.reactiveState = reactiveState as any;
 	
-				this.addIdbSetJob(async () => {
-					const cache = await get(this.registryCacheKeyName);
-					if (cache[key] !== value) {
-						cache[key] = value;
-						await set(this.registryCacheKeyName, cache);
+		if ($i) {
+			// なぜかsetTimeoutしないとapi関数内でエラーになる(おそらく循環参照してることに原因がありそう)
+			window.setTimeout(() => {
+				api('i/registry/get-all', { scope: ['client', this.key] }).then(kvs => {
+					const cache = {};
+					for (const [k, v] of Object.entries(def)) {
+						if (v.where === 'account') {
+							if (Object.prototype.hasOwnProperty.call(kvs, k)) {
+								state[k] = kvs[k];
+								reactiveState[k].value = kvs[k];
+								cache[k] = kvs[k];
+							} else {
+								state[k] = v.default;
+								reactiveState[k].value = v.default;
+							}
+						}
 					}
+					localStorage.setItem(this.keyForLocalStorage + '::cache::' + $i.id, JSON.stringify(cache));
 				});
+			}, 1);
+			// streamingのuser storage updateイベントを監視して更新
+			connection?.on('registryUpdated', ({ scope, key, value }: { scope: string[], key: keyof T, value: T[typeof key]['default'] }) => {
+				if (scope.length !== 2 || scope[0] !== 'client' || scope[1] !== this.key || this.state[key] === value) return;
+
+				this.state[key] = value;
+				this.reactiveState[key].value = value;
+
+				const cache = JSON.parse(localStorage.getItem(this.keyForLocalStorage + '::cache::' + $i.id) || '{}');
+				if (cache[key] !== value) {
+					cache[key] = value;
+					localStorage.setItem(this.keyForLocalStorage + '::cache::' + $i.id, JSON.stringify(cache));
+				}
 			});
 		}
 	}
 
-	private load(): Promise<void> {
-		return new Promise((resolve, reject) => {
-			if ($i) {
-				// api関数と循環参照なので一応setTimeoutしておく
-				window.setTimeout(async () => {
-					await defaultStore.ready;
+	public set<K extends keyof T>(key: K, value: T[K]['default']): void {
+		if (_DEV_) console.log('set', key, value);
 
-					api('i/registry/get-all', { scope: ['client', this.key] })
-					.then(kvs => {
-						const cache: Partial<T> = {};
-						for (const [k, v] of Object.entries(this.def) as [keyof T, T[keyof T]['default']][]) {
-							if (v.where === 'account') {
-								if (Object.prototype.hasOwnProperty.call(kvs, k)) {
-									this.reactiveState[k].value = this.state[k] = (kvs as Partial<T>)[k];
-									cache[k] = (kvs as Partial<T>)[k];
-								} else {
-									this.reactiveState[k].value = this.state[k] = v.default;
-								}
-							}
-						}
-	
-						return set(this.registryCacheKeyName, cache);
-					})
-					.then(() => resolve());
-				}, 1);
+		this.state[key] = value;
+		this.reactiveState[key].value = value;
+
+		switch (this.def[key].where) {
+			case 'device': {
+				const deviceState = JSON.parse(localStorage.getItem(this.keyForLocalStorage) || '{}');
+				deviceState[key] = value;
+				localStorage.setItem(this.keyForLocalStorage, JSON.stringify(deviceState));
+				break;
 			}
-
-			resolve();
-		});
-	}
-
-	public set<K extends keyof T>(key: K, value: T[K]['default']): Promise<void> {
-		// IndexedDBやBroadcastChannelで扱うために単純なオブジェクトにする
-		// (JSON.parse(JSON.stringify(value))の代わり)
-		const rawValue = deepcopy(value);
-
-		if (_DEV_) console.log('set', key, rawValue, value);
-
-		this.reactiveState[key].value = this.state[key] = rawValue;
-
-		return this.addIdbSetJob(async () => {
-			if (_DEV_) console.log(`set ${key} start`);
-			switch (this.def[key].where) {
-				case 'device': {
-					this.pizzaxChannel.postMessage({
-						where: 'device',
-						key,
-						value: rawValue,
-					});
-					const deviceState = await get(this.deviceStateKeyName) || {};
-					deviceState[key] = rawValue;
-					await set(this.deviceStateKeyName, deviceState);
-					break;
-				}
-				case 'deviceAccount': {
-					if ($i == null) break;
-					this.pizzaxChannel.postMessage({
-						where: 'deviceAccount',
-						key,
-						value: rawValue,
-						userId: $i.id,
-					});
-					const deviceAccountState = await get(this.deviceAccountStateKeyName) || {};
-					deviceAccountState[key] = rawValue;
-					await set(this.deviceAccountStateKeyName, deviceAccountState);
-					break;
-				}
-				case 'account': {
-					if ($i == null) break;
-					const cache = await get(this.registryCacheKeyName) || {};
-					cache[key] = rawValue;
-					await set(this.registryCacheKeyName, cache);
-					await api('i/registry/set', {
-						scope: ['client', this.key],
-						key: key.toString(),
-						value: rawValue,
-					});
-					break;
-				}
+			case 'deviceAccount': {
+				if ($i == null) break;
+				const deviceAccountState = JSON.parse(localStorage.getItem(this.keyForLocalStorage + '::' + $i.id) || '{}');
+				deviceAccountState[key] = value;
+				localStorage.setItem(this.keyForLocalStorage + '::' + $i.id, JSON.stringify(deviceAccountState));
+				break;
 			}
-			if (_DEV_) console.log(`set ${key} complete`);
-		});
+			case 'account': {
+				if ($i == null) break;
+				const cache = JSON.parse(localStorage.getItem(this.keyForLocalStorage + '::cache::' + $i.id) || '{}');
+				cache[key] = value;
+				localStorage.setItem(this.keyForLocalStorage + '::cache::' + $i.id, JSON.stringify(cache));
+				api('i/registry/set', {
+					scope: ['client', this.key],
+					key: key,
+					value: value,
+				});
+				break;
+			}
+		}
 	}
 
 	public push<K extends keyof T>(key: K, value: ArrayElement<T[K]['default']>): void {
@@ -213,7 +132,6 @@ export class Storage<T extends StateDef> {
 
 	public reset(key: keyof T) {
 		this.set(key, this.def[key].default);
-		return this.def[key].default;
 	}
 
 	/**
@@ -248,25 +166,4 @@ export class Storage<T extends StateDef> {
 			},
 		};
 	}
-
-	// localStorage => indexedDBのマイグレーション
-	private async migrate() {
-		const deviceState = localStorage.getItem(this.deviceStateKeyName);
-		if (deviceState) { 
-			await set(this.deviceStateKeyName, JSON.parse(deviceState));
-			localStorage.removeItem(this.deviceStateKeyName);
-		}
-
-		const deviceAccountState = $i && localStorage.getItem(this.deviceAccountStateKeyName);
-		if ($i && deviceAccountState) {
-			await set(this.deviceAccountStateKeyName, JSON.parse(deviceAccountState));
-			localStorage.removeItem(this.deviceAccountStateKeyName);
-		}
-
-		const registryCache = $i && localStorage.getItem(this.registryCacheKeyName);
-		if ($i && registryCache) {
-			await set(this.registryCacheKeyName, JSON.parse(registryCache));
-			localStorage.removeItem(this.registryCacheKeyName);
-		}
-	}
 }
diff --git a/packages/client/src/scripts/unison-reload.ts b/packages/client/src/scripts/unison-reload.ts
index b5afe9b07..59af584c1 100644
--- a/packages/client/src/scripts/unison-reload.ts
+++ b/packages/client/src/scripts/unison-reload.ts
@@ -1,3 +1,4 @@
+// SafariがBroadcastChannel未実装なのでライブラリを使う
 import { BroadcastChannel } from 'broadcast-channel';
 
 export const reloadChannel = new BroadcastChannel<string | null>('reload');
diff --git a/packages/client/src/store.ts b/packages/client/src/store.ts
index b83904b6a..3971214af 100644
--- a/packages/client/src/store.ts
+++ b/packages/client/src/store.ts
@@ -303,16 +303,6 @@ export class ColdDeviceStorage {
 		}
 	}
 
-	public static getAll(): Partial<typeof this.default> {
-		return (Object.keys(this.default) as (keyof typeof this.default)[]).reduce((acc, key) => {
-			const value = localStorage.getItem(PREFIX + key);
-			if (value != null) {
-				acc[key] = JSON.parse(value);
-			}
-			return acc;
-		}, {} as any);
-	}
-
 	public static set<T extends keyof typeof ColdDeviceStorage.default>(key: T, value: typeof ColdDeviceStorage.default[T]): void {
 		// 呼び出し側のバグ等で undefined が来ることがある
 		// undefined を文字列として localStorage に入れると参照する際の JSON.parse でコケて不具合の元になるため無視
diff --git a/packages/client/tsconfig.json b/packages/client/tsconfig.json
index 2e968ca7f..ae86db54e 100644
--- a/packages/client/tsconfig.json
+++ b/packages/client/tsconfig.json
@@ -11,8 +11,7 @@
 		"sourceMap": false,
 		"target": "es2017",
 		"module": "esnext",
-		"moduleResolution": "node",
-		"allowSyntheticDefaultImports": true,
+		"moduleResolution": "node"
 		"removeComments": false,
 		"noLib": false,
 		"strict": true,
diff --git a/yarn.lock b/yarn.lock
index 9ce17130f..8ac348436 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5067,7 +5067,6 @@ __metadata:
     cross-env: 7.0.3
     cypress: 11.1.0
     date-fns: 2.29.3
-    deepcopy: 2.1.0
     escape-regexp: 0.0.1
     eslint: 8.28.0
     eslint-plugin-import: 2.26.0
@@ -6067,15 +6066,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"deepcopy@npm:2.1.0":
-  version: 2.1.0
-  resolution: "deepcopy@npm:2.1.0"
-  dependencies:
-    type-detect: ^4.0.8
-  checksum: 7890ccaa8ad672bdc33d02626d13666bfbb33a68f7c6e8921a348b962b77edc4daf7f1301a789ec74a97e7f0acd611099c5cdd1e8b32ce93287819722f57b92e
-  languageName: node
-  linkType: hard
-
 "deepmerge@npm:^4.2.2":
   version: 4.2.2
   resolution: "deepmerge@npm:4.2.2"
@@ -16564,7 +16554,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"type-detect@npm:4.0.8, type-detect@npm:^4.0.8":
+"type-detect@npm:4.0.8":
   version: 4.0.8
   resolution: "type-detect@npm:4.0.8"
   checksum: 62b5628bff67c0eb0b66afa371bd73e230399a8d2ad30d852716efcc4656a7516904570cd8631a49a3ce57c10225adf5d0cbdcb47f6b0255fe6557c453925a15