diff --git a/packages/backend/src/core/FanoutTimelineService.ts b/packages/backend/src/core/FanoutTimelineService.ts
index 654a035a5..9b2678fbc 100644
--- a/packages/backend/src/core/FanoutTimelineService.ts
+++ b/packages/backend/src/core/FanoutTimelineService.ts
@@ -17,6 +17,7 @@ export type FanoutTimelineName =
 	| `localTimeline` // replies are not included
 	| `localTimelineWithFiles` // only non-reply notes with files are included
 	| `localTimelineWithReplies` // only replies are included
+	| `localTimelineWithReplyTo:${string}` // Only replies to specific local user are included. Parameter is reply user id.
 
 	// antenna
 	| `antennaTimeline:${string}`
diff --git a/packages/backend/src/core/NoteCreateService.ts b/packages/backend/src/core/NoteCreateService.ts
index 0110ebaf5..45dfbb87a 100644
--- a/packages/backend/src/core/NoteCreateService.ts
+++ b/packages/backend/src/core/NoteCreateService.ts
@@ -933,6 +933,9 @@ export class NoteCreateService implements OnApplicationShutdown {
 
 				if (note.visibility === 'public' && note.userHost == null) {
 					this.fanoutTimelineService.push('localTimelineWithReplies', note.id, 300, r);
+					if (note.replyUserHost == null) {
+						this.fanoutTimelineService.push(`localTimelineWithReplyTo:${note.replyUserId}`, note.id, 300 / 10, r);
+					}
 				}
 			} else {
 				this.fanoutTimelineService.push(`userTimeline:${user.id}`, note.id, note.userHost == null ? meta.perLocalUserUserTimelineCacheMax : meta.perRemoteUserUserTimelineCacheMax, r);
diff --git a/packages/backend/src/server/api/endpoints/notes/local-timeline.ts b/packages/backend/src/server/api/endpoints/notes/local-timeline.ts
index e8ba39bbf..3fd4dc83f 100644
--- a/packages/backend/src/server/api/endpoints/notes/local-timeline.ts
+++ b/packages/backend/src/server/api/endpoints/notes/local-timeline.ts
@@ -42,7 +42,7 @@ export const meta = {
 		bothWithRepliesAndWithFiles: {
 			message: 'Specifying both withReplies and withFiles is not supported',
 			code: 'BOTH_WITH_REPLIES_AND_WITH_FILES',
-			id: 'dd9c8400-1cb5-4eef-8a31-200c5f933793'
+			id: 'dd9c8400-1cb5-4eef-8a31-200c5f933793',
 		},
 	},
 } as const;
@@ -116,9 +116,12 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				allowPartial: ps.allowPartial,
 				me,
 				useDbFallback: serverSettings.enableFanoutTimelineDbFallback,
-				redisTimelines: ps.withFiles ? ['localTimelineWithFiles'] : ['localTimeline', 'localTimelineWithReplies'],
+				redisTimelines:
+					ps.withFiles ? ['localTimelineWithFiles']
+					: ps.withReplies ? ['localTimeline', 'localTimelineWithReplies']
+					: me ? ['localTimeline', `localTimelineWithReplyTo:${me.id}`]
+					: ['localTimeline'],
 				alwaysIncludeMyNotes: true,
-				excludeReplies: !ps.withReplies,
 				excludePureRenotes: !ps.withRenotes,
 				dbFallback: async (untilId, sinceId, limit) => await this.getFromDb({
 					untilId,