diff --git a/CHANGELOG.md b/CHANGELOG.md
index f067de292..65ee5ecfd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,11 +5,19 @@
 - 
 
 ### Bugfixes
-x
+- 
 
 You should also include the user name that made the change.
 -->
 
+## 13.x.x (unreleased)
+
+### Improvements
+- enhance(client): DM作成時にメンションも含むように
+
+### Bugfixes
+- 
+
 ## 13.9.2 (2023/03/06)
 
 ### Improvements
diff --git a/packages/frontend/src/components/MkPostForm.vue b/packages/frontend/src/components/MkPostForm.vue
index 09f672be7..0de15f2eb 100644
--- a/packages/frontend/src/components/MkPostForm.vue
+++ b/packages/frontend/src/components/MkPostForm.vue
@@ -422,6 +422,10 @@ function pushVisibleUser(user) {
 function addVisibleUser() {
 	os.selectUser().then(user => {
 		pushVisibleUser(user);
+
+		if (!text.includes(`@${user.username}`)) {
+			text = `@${Acct.toString(user)} ${text}`;
+		}
 	});
 }
 
diff --git a/packages/frontend/src/scripts/get-user-menu.ts b/packages/frontend/src/scripts/get-user-menu.ts
index 5170ca4c8..f5aa551bd 100644
--- a/packages/frontend/src/scripts/get-user-menu.ts
+++ b/packages/frontend/src/scripts/get-user-menu.ts
@@ -111,7 +111,7 @@ export function getUserMenu(user: misskey.entities.UserDetailed, router: Router
 		icon: 'ti ti-mail',
 		text: i18n.ts.sendMessage,
 		action: () => {
-			os.post({ specified: user });
+			os.post({ specified: user, initialText: `@${user.username} ` });
 		},
 	}, null, {
 		type: 'parent',