diff --git a/packages/frontend/src/components/global/NestedRouterView.vue b/packages/frontend/src/components/global/NestedRouterView.vue
index 40ee21c674..5b22d0b7a8 100644
--- a/packages/frontend/src/components/global/NestedRouterView.vue
+++ b/packages/frontend/src/components/global/NestedRouterView.vue
@@ -15,12 +15,12 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <script lang="ts" setup>
 import { inject, onBeforeUnmount, provide, ref, shallowRef } from 'vue';
-import type { IRouter, Resolved } from '@/nirax.js';
+import type { Router, Resolved } from '@/router.js';
 import MkLoadingPage from '@/pages/_loading_.vue';
 import { DI } from '@/di.js';
 
 const props = defineProps<{
-	router?: IRouter;
+	router?: Router;
 }>();
 
 const router = props.router ?? inject(DI.router);
diff --git a/packages/frontend/src/components/global/RouterView.vue b/packages/frontend/src/components/global/RouterView.vue
index 2f1ee6734f..720034a942 100644
--- a/packages/frontend/src/components/global/RouterView.vue
+++ b/packages/frontend/src/components/global/RouterView.vue
@@ -22,14 +22,14 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <script lang="ts" setup>
 import { inject, onBeforeUnmount, provide, ref, shallowRef, computed, nextTick } from 'vue';
-import type { IRouter, Resolved, RouteDef } from '@/nirax.js';
+import type { Router, Resolved, RouteDef } from '@/router.js';
 import { prefer } from '@/preferences.js';
 import { globalEvents } from '@/events.js';
 import MkLoadingPage from '@/pages/_loading_.vue';
 import { DI } from '@/di.js';
 
 const props = defineProps<{
-	router?: IRouter;
+	router?: Router;
 }>();
 
 const router = props.router ?? inject(DI.router);
diff --git a/packages/frontend/src/components/global/StackingRouterView.vue b/packages/frontend/src/components/global/StackingRouterView.vue
index 8f5e6663d8..b94e020072 100644
--- a/packages/frontend/src/components/global/StackingRouterView.vue
+++ b/packages/frontend/src/components/global/StackingRouterView.vue
@@ -42,7 +42,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <script lang="ts" setup>
 import { inject, onBeforeUnmount, provide, ref, shallowRef, computed, nextTick } from 'vue';
-import type { IRouter, Resolved, RouteDef } from '@/nirax.js';
+import type { Router, Resolved, RouteDef } from '@/router.js';
 import { prefer } from '@/preferences.js';
 import { globalEvents } from '@/events.js';
 import MkLoadingPage from '@/pages/_loading_.vue';
@@ -50,7 +50,7 @@ import { DI } from '@/di.js';
 import { deepEqual } from '@/utility/deep-equal.js';
 
 const props = defineProps<{
-	router?: IRouter;
+	router?: Router;
 }>();
 
 const router = props.router ?? inject(DI.router);
diff --git a/packages/frontend/src/di.ts b/packages/frontend/src/di.ts
index 2afe35550d..e9b2c2b650 100644
--- a/packages/frontend/src/di.ts
+++ b/packages/frontend/src/di.ts
@@ -4,11 +4,11 @@
  */
 
 import type { InjectionKey, Ref } from 'vue';
-import type { IRouter } from '@/nirax.js';
+import type { Router } from '@/router.js';
 
 export const DI = {
 	routerCurrentDepth: Symbol() as InjectionKey<number>,
-	router: Symbol() as InjectionKey<IRouter>,
+	router: Symbol() as InjectionKey<Router>,
 	mock: Symbol() as InjectionKey<boolean>,
 	pageMetadata: Symbol() as InjectionKey<Ref<Record<string, any>>>,
 };
diff --git a/packages/frontend/src/nirax.ts b/packages/frontend/src/router.ts
similarity index 79%
rename from packages/frontend/src/nirax.ts
rename to packages/frontend/src/router.ts
index 03c8b43aae..c6f3937cde 100644
--- a/packages/frontend/src/nirax.ts
+++ b/packages/frontend/src/router.ts
@@ -103,88 +103,7 @@ function parsePath(path: string): ParsedPath {
 	return res;
 }
 
-export interface IRouter extends EventEmitter<RouterEvent> {
-	current: Resolved;
-	currentRef: ShallowRef<Resolved>;
-	currentRoute: ShallowRef<RouteDef>;
-	navHook: ((path: string, flag?: RouterFlag) => boolean) | null;
-
-	/**
-	 * ルートの初期化（eventListenerの定義後に必ず呼び出すこと）
-	 */
-	init(): void;
-
-	resolve(path: string): Resolved | null;
-
-	getCurrentPath(): string;
-
-	push(path: string, flag?: RouterFlag): void;
-
-	replace(path: string): void;
-
-	/** @see EventEmitter */
-	eventNames(): Array<EventEmitter.EventNames<RouterEvent>>;
-
-	/** @see EventEmitter */
-	listeners<T extends EventEmitter.EventNames<RouterEvent>>(
-		event: T
-	): Array<EventEmitter.EventListener<RouterEvent, T>>;
-
-	/** @see EventEmitter */
-	listenerCount(
-		event: EventEmitter.EventNames<RouterEvent>
-	): number;
-
-	/** @see EventEmitter */
-	emit<T extends EventEmitter.EventNames<RouterEvent>>(
-		event: T,
-		...args: EventEmitter.EventArgs<RouterEvent, T>
-	): boolean;
-
-	/** @see EventEmitter */
-	on<T extends EventEmitter.EventNames<RouterEvent>>(
-		event: T,
-		fn: EventEmitter.EventListener<RouterEvent, T>,
-		context?: any
-	): this;
-
-	/** @see EventEmitter */
-	addListener<T extends EventEmitter.EventNames<RouterEvent>>(
-		event: T,
-		fn: EventEmitter.EventListener<RouterEvent, T>,
-		context?: any
-	): this;
-
-	/** @see EventEmitter */
-	once<T extends EventEmitter.EventNames<RouterEvent>>(
-		event: T,
-		fn: EventEmitter.EventListener<RouterEvent, T>,
-		context?: any
-	): this;
-
-	/** @see EventEmitter */
-	removeListener<T extends EventEmitter.EventNames<RouterEvent>>(
-		event: T,
-		fn?: EventEmitter.EventListener<RouterEvent, T>,
-		context?: any,
-		once?: boolean | undefined
-	): this;
-
-	/** @see EventEmitter */
-	off<T extends EventEmitter.EventNames<RouterEvent>>(
-		event: T,
-		fn?: EventEmitter.EventListener<RouterEvent, T>,
-		context?: any,
-		once?: boolean | undefined
-	): this;
-
-	/** @see EventEmitter */
-	removeAllListeners(
-		event?: EventEmitter.EventNames<RouterEvent>
-	): this;
-}
-
-export class Router extends EventEmitter<RouterEvent> implements IRouter {
+export class Router extends EventEmitter<RouterEvent> {
 	private routes: RouteDef[];
 	public current: Resolved;
 	public currentRef: ShallowRef<Resolved>;
@@ -367,7 +286,6 @@ export class Router extends EventEmitter<RouterEvent> implements IRouter {
 			res.props.set('showLoginPopup', true);
 		}
 
-		const isSamePath = beforePath === path;
 		this.current = res;
 		this.currentRef.value = res;
 		this.currentRoute.value = res.route;
diff --git a/packages/frontend/src/router/definition.ts b/packages/frontend/src/router/definition.ts
index 9a81032cc8..923903ec3d 100644
--- a/packages/frontend/src/router/definition.ts
+++ b/packages/frontend/src/router/definition.ts
@@ -5,8 +5,8 @@
 
 import { defineAsyncComponent } from 'vue';
 import type { AsyncComponentLoader } from 'vue';
-import type { IRouter, RouteDef } from '@/nirax.js';
-import { Router } from '@/nirax.js';
+import type { RouteDef } from '@/router.js';
+import { Router } from '@/router.js';
 import { $i, iAmModerator } from '@/i.js';
 import MkLoading from '@/pages/_loading_.vue';
 import MkError from '@/pages/_error_.vue';
@@ -578,6 +578,6 @@ const routes: RouteDef[] = [{
 	component: page(() => import('@/pages/not-found.vue')),
 }];
 
-export function createMainRouter(path: string): IRouter {
+export function createMainRouter(path: string): Router {
 	return new Router(routes, path, !!$i, page(() => import('@/pages/not-found.vue')));
 }
diff --git a/packages/frontend/src/router/main.ts b/packages/frontend/src/router/main.ts
index 2373c87717..f294af059d 100644
--- a/packages/frontend/src/router/main.ts
+++ b/packages/frontend/src/router/main.ts
@@ -4,7 +4,7 @@
  */
 
 import { EventEmitter } from 'eventemitter3';
-import type { IRouter, Resolved, RouteDef, RouterEvent, RouterFlag } from '@/nirax.js';
+import type { Router, Resolved, RouteDef, RouterEvent, RouterFlag } from '@/router.js';
 
 import type { App, ShallowRef } from 'vue';
 import { analytics } from '@/analytics.js';
@@ -13,7 +13,7 @@ import { analytics } from '@/analytics.js';
  * {@link Router}による画面遷移を可能とするために{@link mainRouter}をセットアップする。
  * また、{@link Router}のインスタンスを作成するためのファクトリも{@link provide}経由で公開する（`routerFactory`というキーで取得可能）
  */
-export function setupRouter(app: App, routerFactory: ((path: string) => IRouter)): void {
+export function setupRouter(app: App, routerFactory: ((path: string) => Router)): void {
 	app.provide('routerFactory', routerFactory);
 
 	const mainRouter = routerFactory(location.pathname + location.search + location.hash);
@@ -43,7 +43,7 @@ export function setupRouter(app: App, routerFactory: ((path: string) => IRouter)
 	setMainRouter(mainRouter);
 }
 
-function getMainRouter(): IRouter {
+function getMainRouter(): Router {
 	const router = mainRouterHolder;
 	if (!router) {
 		throw new Error('mainRouter is not found.');
@@ -56,7 +56,7 @@ function getMainRouter(): IRouter {
  * メインルータを設定する。一度設定すると、それ以降は変更できない。
  * {@link setupRouter}から呼び出されることのみを想定している。
  */
-export function setMainRouter(router: IRouter) {
+export function setMainRouter(router: Router) {
 	if (mainRouterHolder) {
 		throw new Error('mainRouter is already exists.');
 	}
@@ -69,10 +69,10 @@ export function setMainRouter(router: IRouter) {
  * {@link mainRouter}は起動シーケンスの一部にて初期化されるため、僅かにundefinedになる期間がある。
  * その僅かな期間のためだけに型をundefined込みにしたくないのでこのクラスを緩衝材として使用する。
  */
-class MainRouterProxy implements IRouter {
-	private supplier: () => IRouter;
+class MainRouterProxy implements Router {
+	private supplier: () => Router;
 
-	constructor(supplier: () => IRouter) {
+	constructor(supplier: () => Router) {
 		this.supplier = supplier;
 	}
 
@@ -194,6 +194,6 @@ class MainRouterProxy implements IRouter {
 	}
 }
 
-let mainRouterHolder: IRouter | null = null;
+let mainRouterHolder: Router | null = null;
 
-export const mainRouter: IRouter = new MainRouterProxy(getMainRouter);
+export const mainRouter: Router = new MainRouterProxy(getMainRouter);
diff --git a/packages/frontend/src/router/supplier.ts b/packages/frontend/src/router/supplier.ts
index bdeb47cfd8..3c05b41c20 100644
--- a/packages/frontend/src/router/supplier.ts
+++ b/packages/frontend/src/router/supplier.ts
@@ -4,15 +4,15 @@
  */
 
 import { inject } from 'vue';
-import type { IRouter } from '@/nirax.js';
+import type { Router } from '@/router.js';
 import { mainRouter } from '@/router/main.js';
 import { DI } from '@/di.js';
 
 /**
  * メインの{@link Router}を取得する。
- * あらかじめ{@link setupRouter}を実行しておく必要がある（{@link provide}により{@link IRouter}のインスタンスを注入可能であるならばこの限りではない）
+ * あらかじめ{@link setupRouter}を実行しておく必要がある（{@link provide}により{@link Router}のインスタンスを注入可能であるならばこの限りではない）
  */
-export function useRouter(): IRouter {
+export function useRouter(): Router {
 	return inject(DI.router, null) ?? mainRouter;
 }
 
@@ -20,8 +20,8 @@ export function useRouter(): IRouter {
  * 任意の{@link Router}を取得するためのファクトリを取得する。
  * あらかじめ{@link setupRouter}を実行しておく必要がある。
  */
-export function useRouterFactory(): (path: string) => IRouter {
-	const factory = inject<(path: string) => IRouter>('routerFactory');
+export function useRouterFactory(): (path: string) => Router {
+	const factory = inject<(path: string) => Router>('routerFactory');
 	if (!factory) {
 		console.error('routerFactory is not defined.');
 		throw new Error('routerFactory is not defined.');
diff --git a/packages/frontend/src/utility/get-user-menu.ts b/packages/frontend/src/utility/get-user-menu.ts
index 496e021e99..c28b2db6d7 100644
--- a/packages/frontend/src/utility/get-user-menu.ts
+++ b/packages/frontend/src/utility/get-user-menu.ts
@@ -7,7 +7,7 @@ import { toUnicode } from 'punycode.js';
 import { defineAsyncComponent, ref, watch } from 'vue';
 import * as Misskey from 'misskey-js';
 import { host, url } from '@@/js/config.js';
-import type { IRouter } from '@/nirax.js';
+import type { Router } from '@/router.js';
 import type { MenuItem } from '@/types/menu.js';
 import { i18n } from '@/i18n.js';
 import { copyToClipboard } from '@/utility/copy-to-clipboard.js';
@@ -21,7 +21,7 @@ import { genEmbedCode } from '@/utility/get-embed-code.js';
 import { prefer } from '@/preferences.js';
 import { getPluginHandlers } from '@/plugin.js';
 
-export function getUserMenu(user: Misskey.entities.UserDetailed, router: IRouter = mainRouter) {
+export function getUserMenu(user: Misskey.entities.UserDetailed, router: Router = mainRouter) {
 	const meId = $i ? $i.id : null;
 
 	const cleanups = [] as (() => void)[];
diff --git a/packages/frontend/src/utility/lookup.ts b/packages/frontend/src/utility/lookup.ts
index d3a2d854a0..e0b945e49b 100644
--- a/packages/frontend/src/utility/lookup.ts
+++ b/packages/frontend/src/utility/lookup.ts
@@ -6,7 +6,7 @@
 import * as os from '@/os.js';
 import { misskeyApi } from '@/utility/misskey-api.js';
 import { i18n } from '@/i18n.js';
-import { Router } from '@/nirax.js';
+import { Router } from '@/router.js';
 import { mainRouter } from '@/router/main.js';
 
 export async function lookup(router?: Router) {