diff --git a/packages/backend/migration/1652210810723-PGroonga.js b/packages/backend/migration/1652210810723-PGroonga.js
new file mode 100644
index 000000000..bd3fee34e
--- /dev/null
+++ b/packages/backend/migration/1652210810723-PGroonga.js
@@ -0,0 +1,11 @@
+export class PGroonga1652210810723 {
+    name = 'PGroonga1652210810723'
+
+    async up(queryRunner) {
+        await queryRunner.query(`CREATE INDEX "IDX_f27f5d88941e57442be75ba9c8" ON "note" USING "pgroonga" ("text")`);
+    }
+
+    async down(queryRunner) {
+        await queryRunner.query(`DROP INDEX "public"."IDX_f27f5d88941e57442be75ba9c8"`);
+    }
+}
diff --git a/packages/backend/migration/1652213168020-PGroongaUserName.js b/packages/backend/migration/1652213168020-PGroongaUserName.js
new file mode 100644
index 000000000..9e1e75ece
--- /dev/null
+++ b/packages/backend/migration/1652213168020-PGroongaUserName.js
@@ -0,0 +1,11 @@
+export class PGroongaUserName1652213168020 {
+    name = 'PGroongaUserName1652213168020'
+
+    async up(queryRunner) {
+        await queryRunner.query(`CREATE INDEX "IDX_065d4d8f3b5adb4a08841eae3c" ON "user" USING "pgroonga" ("name" pgroonga_varchar_full_text_search_ops_v2)`);
+    }
+
+    async down(queryRunner) {
+        await queryRunner.query(`DROP INDEX "public"."IDX_065d4d8f3b5adb4a08841eae3c"`);
+    }
+}
diff --git a/packages/backend/migration/1652213556290-PGroongaUserDescription.js b/packages/backend/migration/1652213556290-PGroongaUserDescription.js
new file mode 100644
index 000000000..7216438ab
--- /dev/null
+++ b/packages/backend/migration/1652213556290-PGroongaUserDescription.js
@@ -0,0 +1,11 @@
+export class PGroongaUserDescription1652213556290 {
+    name = 'PGroongaUserDescription1652213556290'
+
+    async up(queryRunner) {
+        await queryRunner.query(`CREATE INDEX "IDX_fcb770976ff8240af5799e3ffc" ON "user_profile" USING "pgroonga" ("description" pgroonga_varchar_full_text_search_ops_v2) `);
+    }
+
+    async down(queryRunner) {
+        await queryRunner.query(`DROP INDEX "public"."IDX_fcb770976ff8240af5799e3ffc"`);
+    }
+}
diff --git a/packages/backend/migration/1727542814489-Pgroonga.js b/packages/backend/migration/1727542814489-Pgroonga.js
new file mode 100644
index 000000000..b8e3e4a46
--- /dev/null
+++ b/packages/backend/migration/1727542814489-Pgroonga.js
@@ -0,0 +1,16 @@
+export class Pgroonga1727542814489 {
+    name = 'Pgroonga1727542814489'
+
+    async up(queryRunner) {
+			await queryRunner.query(`CREATE INDEX "IDX_f27f5d88941e57442be75ba9c8" ON "note" USING "pgroonga" ("text")`);
+			await queryRunner.query(`CREATE INDEX "IDX_065d4d8f3b5adb4a08841eae3c" ON "user" USING "pgroonga" ("name" pgroonga_varchar_full_text_search_ops_v2)`);
+			await queryRunner.query(`CREATE INDEX "IDX_fcb770976ff8240af5799e3ffc" ON "user_profile" USING "pgroonga" ("description" pgroonga_varchar_full_text_search_ops_v2) `);
+
+    }
+
+    async down(queryRunner) {
+			await queryRunner.query(`DROP INDEX "public"."IDX_f27f5d88941e57442be75ba9c8"`);
+			await queryRunner.query(`DROP INDEX "public"."IDX_065d4d8f3b5adb4a08841eae3c"`);
+			await queryRunner.query(`DROP INDEX "public"."IDX_fcb770976ff8240af5799e3ffc"`);
+		}
+}
\ No newline at end of file
diff --git a/packages/backend/src/core/SearchService.ts b/packages/backend/src/core/SearchService.ts
index edfc47037..42a32220d 100644
--- a/packages/backend/src/core/SearchService.ts
+++ b/packages/backend/src/core/SearchService.ts
@@ -215,7 +215,7 @@ export class SearchService {
 			}
 
 			query
-				.andWhere('note.text ILIKE :q', { q: `%${ sqlLikeEscape(q) }%` })
+				.andWhere('note.text &@~ :q', { q: sqlLikeEscape(q) })
 				.innerJoinAndSelect('note.user', 'user')
 				.leftJoinAndSelect('note.reply', 'reply')
 				.leftJoinAndSelect('note.renote', 'renote')
diff --git a/packages/backend/src/models/Note.ts b/packages/backend/src/models/Note.ts
index 9a95c6faa..e21048dee 100644
--- a/packages/backend/src/models/Note.ts
+++ b/packages/backend/src/models/Note.ts
@@ -50,6 +50,7 @@ export class MiNote {
 	public threadId: string | null;
 
 	// TODO: varcharにしたい
+	@Index() // USING pgroonga
 	@Column('text', {
 		nullable: true,
 	})
diff --git a/packages/backend/src/models/User.ts b/packages/backend/src/models/User.ts
index 805a1e75a..76337dab4 100644
--- a/packages/backend/src/models/User.ts
+++ b/packages/backend/src/models/User.ts
@@ -49,6 +49,7 @@ export class MiUser {
 	})
 	public usernameLower: string;
 
+	@Index() // USING pgroonga pgroonga_varchar_full_text_search_ops_v2
 	@Column('varchar', {
 		length: 128, nullable: true,
 		comment: 'The name of the User.',
diff --git a/packages/backend/src/models/UserProfile.ts b/packages/backend/src/models/UserProfile.ts
index 554455529..5f1a7a7d1 100644
--- a/packages/backend/src/models/UserProfile.ts
+++ b/packages/backend/src/models/UserProfile.ts
@@ -36,6 +36,7 @@ export class MiUserProfile {
 	})
 	public birthday: string | null;
 
+	@Index() // USING pgroonga pgroonga_varchar_full_text_search_ops_v2
 	@Column('varchar', {
 		length: 2048, nullable: true,
 		comment: 'The description (bio) of the User.',
diff --git a/packages/backend/src/server/api/endpoints/notes/search.ts b/packages/backend/src/server/api/endpoints/notes/search.ts
index 3fe19806e..a26c49c94 100644
--- a/packages/backend/src/server/api/endpoints/notes/search.ts
+++ b/packages/backend/src/server/api/endpoints/notes/search.ts
@@ -31,6 +31,11 @@ export const meta = {
 			code: 'UNAVAILABLE',
 			id: '0b44998d-77aa-4427-80d0-d2c9b8523011',
 		},
+		noSuchNote: {
+			message: 'Query is empty.',
+			code: 'QUERY_IS_EMPTY',
+			id: 'd0410b51-f409-4667-8118-cfe999e453c3',
+		},
 	},
 } as const;
 
@@ -62,6 +67,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 		private roleService: RoleService,
 	) {
 		super(meta, paramDef, async (ps, me) => {
+			if (ps.query.trim().length === 0) throw new ApiError(meta.errors.noSuchNote);
 			const policies = await this.roleService.getUserPolicies(me ? me.id : null);
 			if (!policies.canSearchNotes) {
 				throw new ApiError(meta.errors.unavailable);
diff --git a/packages/backend/src/server/api/endpoints/users/search.ts b/packages/backend/src/server/api/endpoints/users/search.ts
index 0b0136066..6c686a8eb 100644
--- a/packages/backend/src/server/api/endpoints/users/search.ts
+++ b/packages/backend/src/server/api/endpoints/users/search.ts
@@ -63,12 +63,12 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 
 			const nameQuery = this.usersRepository.createQueryBuilder('user')
 				.where(new Brackets(qb => {
-					qb.where('user.name ILIKE :query', { query: '%' + sqlLikeEscape(ps.query) + '%' });
+					qb.where('user.name &@~ :query', { query: ps.query });
 
 					if (isUsername) {
 						qb.orWhere('user.usernameLower LIKE :username', { username: sqlLikeEscape(ps.query.replace('@', '').toLowerCase()) + '%' });
-					} else if (this.userEntityService.validateLocalUsername(ps.query)) { // Also search username if it qualifies as username
-						qb.orWhere('user.usernameLower LIKE :username', { username: '%' + sqlLikeEscape(ps.query.toLowerCase()) + '%' });
+					} else if (userEntityService.validateLocalUsername(ps.query)) { // Also search username if it qualifies as username
+						qb.orWhere('user.usernameLower LIKE :username', { username: ps.query.toLowerCase() + '%' });
 					}
 				}))
 				.andWhere(new Brackets(qb => {
@@ -93,7 +93,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 			if (users.length < ps.limit) {
 				const profQuery = this.userProfilesRepository.createQueryBuilder('prof')
 					.select('prof.userId')
-					.where('prof.description ILIKE :query', { query: '%' + sqlLikeEscape(ps.query) + '%' });
+					.where('prof.description &@~ :query', { query: ps.query });
 
 				if (ps.origin === 'local') {
 					profQuery.andWhere('prof.userHost IS NULL');
diff --git a/pgroonga.diff b/pgroonga.diff
new file mode 100644
index 000000000..c960ba5d9
--- /dev/null
+++ b/pgroonga.diff
@@ -0,0 +1,51 @@
+diff --git a/packages/backend/migration/1652210810723-PGroonga.js b/packages/backend/migration/1652210810723-PGroonga.js
+new file mode 100644
+index 000000000..bd3fee34e
+--- /dev/null
++++ b/packages/backend/migration/1652210810723-PGroonga.js
+@@ -0,0 +1,11 @@
++export class PGroonga1652210810723 {
++    name = 'PGroonga1652210810723'
++
++    async up(queryRunner) {
++        await queryRunner.query(`CREATE INDEX "IDX_f27f5d88941e57442be75ba9c8" ON "note" USING "pgroonga" ("text")`);
++    }
++
++    async down(queryRunner) {
++        await queryRunner.query(`DROP INDEX "public"."IDX_f27f5d88941e57442be75ba9c8"`);
++    }
++}
+diff --git a/packages/backend/migration/1652213168020-PGroongaUserName.js b/packages/backend/migration/1652213168020-PGroongaUserName.js
+new file mode 100644
+index 000000000..9e1e75ece
+--- /dev/null
++++ b/packages/backend/migration/1652213168020-PGroongaUserName.js
+@@ -0,0 +1,11 @@
++export class PGroongaUserName1652213168020 {
++    name = 'PGroongaUserName1652213168020'
++
++    async up(queryRunner) {
++        await queryRunner.query(`CREATE INDEX "IDX_065d4d8f3b5adb4a08841eae3c" ON "user" USING "pgroonga" ("name" pgroonga_varchar_full_text_search_ops_v2)`);
++    }
++
++    async down(queryRunner) {
++        await queryRunner.query(`DROP INDEX "public"."IDX_065d4d8f3b5adb4a08841eae3c"`);
++    }
++}
+diff --git a/packages/backend/migration/1652213556290-PGroongaUserDescription.js b/packages/backend/migration/1652213556290-PGroongaUserDescription.js
+new file mode 100644
+index 000000000..7216438ab
+--- /dev/null
++++ b/packages/backend/migration/1652213556290-PGroongaUserDescription.js
+@@ -0,0 +1,11 @@
++export class PGroongaUserDescription1652213556290 {
++    name = 'PGroongaUserDescription1652213556290'
++
++    async up(queryRunner) {
++        await queryRunner.query(`CREATE INDEX "IDX_fcb770976ff8240af5799e3ffc" ON "user_profile" USING "pgroonga" ("description" pgroonga_varchar_full_text_search_ops_v2) `);
++    }
++
++    async down(queryRunner) {
++        await queryRunner.query(`DROP INDEX "public"."IDX_fcb770976ff8240af5799e3ffc"`);
++    }
++}