diff --git a/packages/frontend/package.json b/packages/frontend/package.json
index c819b5f66c..a8e3e40fdf 100644
--- a/packages/frontend/package.json
+++ b/packages/frontend/package.json
@@ -57,11 +57,9 @@
 		"punycode": "2.3.0",
 		"querystring": "0.2.1",
 		"rollup": "3.29.1",
-		"s-age": "1.1.2",
 		"sanitize-html": "2.11.0",
 		"sass": "1.67.0",
 		"strict-event-emitter-types": "2.0.0",
-		"syuilo-password-strength": "0.0.1",
 		"textarea-caret": "3.1.0",
 		"three": "0.156.1",
 		"throttle-debounce": "5.0.0",
diff --git a/packages/frontend/src/components/MkSignupDialog.form.vue b/packages/frontend/src/components/MkSignupDialog.form.vue
index de9b320da2..60541b256b 100644
--- a/packages/frontend/src/components/MkSignupDialog.form.vue
+++ b/packages/frontend/src/components/MkSignupDialog.form.vue
@@ -77,7 +77,6 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <script lang="ts" setup>
 import { } from 'vue';
-import getPasswordStrength from 'syuilo-password-strength';
 import { toUnicode } from 'punycode/';
 import MkButton from './MkButton.vue';
 import MkInput from './MkInput.vue';
@@ -132,6 +131,30 @@ const shouldDisableSubmitting = $computed((): boolean => {
 		passwordRetypeState !== 'match';
 });
 
+function getPasswordStrength(source: string): number {
+	let strength = 0;
+	let power = 0.018;
+
+	// 英数字
+	if (/[a-zA-Z]/.test(source) && /[0-9]/.test(source)) {
+		power += 0.020;
+	}
+
+	// 大文字と小文字が混ざってたら
+	if (/[a-z]/.test(source) && /[A-Z]/.test(source)) {
+		power += 0.015;
+	}
+
+	// 記号が混ざってたら
+	if (/[!\x22\#$%&@'()*+,-./_]/.test(source)) {
+		power += 0.02;
+	}
+
+	strength = power * source.length;
+
+	return Math.max(0, Math.min(1, strength));
+}
+
 function onChangeUsername(): void {
 	if (username === '') {
 		usernameState = null;
diff --git a/packages/frontend/src/pages/user/home.vue b/packages/frontend/src/pages/user/home.vue
index a8720e1050..8bc6c72440 100644
--- a/packages/frontend/src/pages/user/home.vue
+++ b/packages/frontend/src/pages/user/home.vue
@@ -143,7 +143,6 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <script lang="ts" setup>
 import { defineAsyncComponent, computed, onMounted, onUnmounted, nextTick, watch } from 'vue';
-import calcAge from 's-age';
 import * as Misskey from 'misskey-js';
 import MkNote from '@/components/MkNote.vue';
 import MkFollowButton from '@/components/MkFollowButton.vue';
@@ -167,6 +166,21 @@ import MkNotes from '@/components/MkNotes.vue';
 import { api } from '@/os';
 import { isFfVisibleForMe } from '@/scripts/isFfVisibleForMe';
 
+function calcAge(birthdate: string): number {
+	const date = new Date(birthdate);
+	const now = new Date();
+
+	let yearDiff = now.getFullYear() - date.getFullYear();
+	const monthDiff = now.getMonth() - date.getMonth();
+	const pastDate = now.getDate() < date.getDate();
+
+	if (monthDiff < 0 || (monthDiff === 0 && pastDate)) {
+		yearDiff--;
+	}
+
+	return yearDiff;
+}
+
 const XPhotos = defineAsyncComponent(() => import('./index.photos.vue'));
 const XActivity = defineAsyncComponent(() => import('./index.activity.vue'));
 
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5381169659..a8ff613394 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -766,9 +766,6 @@ importers:
       rollup:
         specifier: 3.29.1
         version: 3.29.1
-      s-age:
-        specifier: 1.1.2
-        version: 1.1.2
       sanitize-html:
         specifier: 2.11.0
         version: 2.11.0
@@ -778,9 +775,6 @@ importers:
       strict-event-emitter-types:
         specifier: 2.0.0
         version: 2.0.0
-      syuilo-password-strength:
-        specifier: 0.0.1
-        version: 0.0.1
       textarea-caret:
         specifier: 3.1.0
         version: 3.1.0
@@ -17327,10 +17321,6 @@ packages:
     dependencies:
       tslib: 2.5.0
 
-  /s-age@1.1.2:
-    resolution: {integrity: sha512-aSN2TlF39WLoZA/6cgYSJZhKt63kJ4EaadejPWjWY9/h4rksIqvfWY3gfd+3uAegSM1IXsA9aWeEhJtkxkFQtA==}
-    dev: false
-
   /safe-array-concat@1.0.0:
     resolution: {integrity: sha512-9dVEFruWIsnie89yym+xWTAYASdpw3CJV7Li/6zBewGf9z2i1j31rP6jnY0pHEO4QZh6N0K11bFjWmdR8UGdPQ==}
     engines: {node: '>=0.4'}
@@ -18274,10 +18264,6 @@ packages:
     hasBin: true
     dev: false
 
-  /syuilo-password-strength@0.0.1:
-    resolution: {integrity: sha512-g9rPT3V1Q4WjWFZ/t5BdGC1mT/FpYnsLdBl+M5e6MlRkuE1RSR+R43wcY/3mKI59B9KEr+vxdWCuWNMD3oNHKA==}
-    dev: false
-
   /tar-fs@2.1.1:
     resolution: {integrity: sha512-V0r2Y9scmbDRLCNex/+hYzvp/zyYjvFbHPNgVTKfQvVrb6guiE/fxP+XblDNR011utopbkex2nM4dHNV6GDsng==}
     dependencies: