diff --git a/CHANGELOG.md b/CHANGELOG.md
index a939fa7621..ebbe22f2f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -28,6 +28,10 @@
 - Fix: nodeinfoにenableMcaptchaとenableTurnstileが無いのを修正
 - エンドポイント`flash/update`の`flashId`以外のパラメータは必須ではなくなりました
 - Fix: 禁止キーワードを含むノートがDelayed Queueに追加されて再処理される問題を修正
+- エンドポイント`admin/emoji/update`の各種修正
+  - 必須パラメータを`id`または`name`のいずれかのみに
+  - `id`の代わりに`name`で絵文字を指定可能に（`id`・`name`両指定時は従来通り`name`を変更する挙動）
+  - `category`および`licence`が指定なしの時勝手にnullに上書きされる挙動を修正
 
 ## 2024.2.0
 
diff --git a/packages/backend/src/core/CustomEmojiService.ts b/packages/backend/src/core/CustomEmojiService.ts
index 64a8c1acdf..edb9335b6e 100644
--- a/packages/backend/src/core/CustomEmojiService.ts
+++ b/packages/backend/src/core/CustomEmojiService.ts
@@ -393,6 +393,11 @@ export class CustomEmojiService implements OnApplicationShutdown {
 		return this.emojisRepository.findOneBy({ id });
 	}
 
+	@bindThis
+	public getEmojiByName(name: string): Promise<MiEmoji | null> {
+		return this.emojisRepository.findOneBy({ name, host: IsNull() });
+	}
+
 	@bindThis
 	public dispose(): void {
 		this.cache.dispose();
diff --git a/packages/backend/src/server/api/endpoints/admin/emoji/update.ts b/packages/backend/src/server/api/endpoints/admin/emoji/update.ts
index a9ff4236d2..22609a16a3 100644
--- a/packages/backend/src/server/api/endpoints/admin/emoji/update.ts
+++ b/packages/backend/src/server/api/endpoints/admin/emoji/update.ts
@@ -57,7 +57,10 @@ export const paramDef = {
 			type: 'string',
 		} },
 	},
-	required: ['id', 'name', 'aliases'],
+	anyOf: [
+		{ required: ['id'] },
+		{ required: ['name'] },
+	],
 } as const;
 
 @Injectable()
@@ -70,27 +73,33 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 	) {
 		super(meta, paramDef, async (ps, me) => {
 			let driveFile;
-
 			if (ps.fileId) {
 				driveFile = await this.driveFilesRepository.findOneBy({ id: ps.fileId });
 				if (driveFile == null) throw new ApiError(meta.errors.noSuchFile);
 			}
-			const emoji = await this.customEmojiService.getEmojiById(ps.id);
-			if (emoji != null) {
-				if (ps.name !== emoji.name) {
+
+			let emojiId;
+			if (ps.id) {
+				emojiId = ps.id;
+				const emoji = await this.customEmojiService.getEmojiById(ps.id);
+				if (!emoji) throw new ApiError(meta.errors.noSuchEmoji);
+				if (ps.name && (ps.name !== emoji.name)) {
 					const isDuplicate = await this.customEmojiService.checkDuplicate(ps.name);
 					if (isDuplicate) throw new ApiError(meta.errors.sameNameEmojiExists);
 				}
 			} else {
-				throw new ApiError(meta.errors.noSuchEmoji);
+				if (!ps.name) throw new Error('Invalid Params unexpectedly passed. This is a BUG. Please report it to the development team.');
+				const emoji = await this.customEmojiService.getEmojiByName(ps.name);
+				if (!emoji) throw new ApiError(meta.errors.noSuchEmoji);
+				emojiId = emoji.id;
 			}
 
-			await this.customEmojiService.update(ps.id, {
+			await this.customEmojiService.update(emojiId, {
 				driveFile,
 				name: ps.name,
-				category: ps.category ?? null,
+				category: ps.category,
 				aliases: ps.aliases,
-				license: ps.license ?? null,
+				license: ps.license,
 				isSensitive: ps.isSensitive,
 				localOnly: ps.localOnly,
 				roleIdsThatCanBeUsedThisEmojiAsReaction: ps.roleIdsThatCanBeUsedThisEmojiAsReaction,
diff --git a/packages/misskey-js/src/autogen/types.ts b/packages/misskey-js/src/autogen/types.ts
index 18bc45b983..07edf19c94 100644
--- a/packages/misskey-js/src/autogen/types.ts
+++ b/packages/misskey-js/src/autogen/types.ts
@@ -7089,13 +7089,13 @@ export type operations = {
       content: {
         'application/json': {
           /** Format: misskey:id */
-          id: string;
-          name: string;
+          id?: string;
+          name?: string;
           /** Format: misskey:id */
           fileId?: string;
           /** @description Use `null` to reset the category. */
           category?: string | null;
-          aliases: string[];
+          aliases?: string[];
           license?: string | null;
           isSensitive?: boolean;
           localOnly?: boolean;