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diff --git a/packages/frontend/assets/room/objects/envelope/envelope.png b/packages/frontend/assets/room/objects/envelope/envelope.png
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diff --git a/packages/frontend/assets/room/objects/envelope/textures/contents.png b/packages/frontend/assets/room/objects/envelope/textures/contents.png
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diff --git a/packages/frontend/assets/room/objects/envelope/textures/envelope.png b/packages/frontend/assets/room/objects/envelope/textures/envelope.png
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diff --git a/packages/frontend/src/utility/room/object-defs.ts b/packages/frontend/src/utility/room/object-defs.ts
index 183f970d9c..ebacc3f4f5 100644
--- a/packages/frontend/src/utility/room/object-defs.ts
+++ b/packages/frontend/src/utility/room/object-defs.ts
@@ -23,6 +23,7 @@ import { desk } from './objects/desk.js';
 import { ductTape } from './objects/ductTape.js';
 import { emptyBento } from './objects/emptyBento.js';
 import { energyDrink } from './objects/energyDrink.js';
+import { envelope } from './objects/envelope.js';
 import { facialTissue } from './objects/facialTissue.js';
 import { hangingTShirt } from './objects/hangingTShirt.js';
 import { keyboard } from './objects/keyboard.js';
@@ -75,6 +76,7 @@ export const OBJECT_DEFS = [
 	ductTape,
 	emptyBento,
 	energyDrink,
+	envelope,
 	facialTissue,
 	hangingTShirt,
 	keyboard,
diff --git a/packages/frontend/src/utility/room/objects/envelope.ts b/packages/frontend/src/utility/room/objects/envelope.ts
new file mode 100644
index 0000000000..c8fc0215e6
--- /dev/null
+++ b/packages/frontend/src/utility/room/objects/envelope.ts
@@ -0,0 +1,21 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { defineObject } from '../engine.js';
+
+export const envelope = defineObject({
+	id: 'envelope',
+	name: 'Envelope',
+	options: {
+		schema: {},
+		default: {},
+	},
+	placement: 'top',
+	createInstance: () => {
+		return {
+			interactions: {},
+		};
+	},
+});