diff --git a/packages/frontend/assets/room/objects/a4-case/a4-case.blend b/packages/frontend/assets/room/objects/a4-case/a4-case.blend
new file mode 100644
index 0000000000..464ed85ce4
Binary files /dev/null and b/packages/frontend/assets/room/objects/a4-case/a4-case.blend differ
diff --git a/packages/frontend/assets/room/objects/a4-case/a4-case.glb b/packages/frontend/assets/room/objects/a4-case/a4-case.glb
new file mode 100644
index 0000000000..fe2365f1ed
Binary files /dev/null and b/packages/frontend/assets/room/objects/a4-case/a4-case.glb differ
diff --git a/packages/frontend/assets/room/objects/mixer/body.af b/packages/frontend/assets/room/objects/mixer/body.af
index 787bd92be5..19f84dbbd8 100644
Binary files a/packages/frontend/assets/room/objects/mixer/body.af and b/packages/frontend/assets/room/objects/mixer/body.af differ
diff --git a/packages/frontend/assets/room/objects/mixer/mixer.blend b/packages/frontend/assets/room/objects/mixer/mixer.blend
index 327f7cdcaf..b087503362 100644
Binary files a/packages/frontend/assets/room/objects/mixer/mixer.blend and b/packages/frontend/assets/room/objects/mixer/mixer.blend differ
diff --git a/packages/frontend/assets/room/objects/mixer/mixer.glb b/packages/frontend/assets/room/objects/mixer/mixer.glb
index 0df428a29c..b94d45653d 100644
Binary files a/packages/frontend/assets/room/objects/mixer/mixer.glb and b/packages/frontend/assets/room/objects/mixer/mixer.glb differ
diff --git a/packages/frontend/assets/room/objects/mixer/textures/body.png b/packages/frontend/assets/room/objects/mixer/textures/body.png
index 3c969b7e38..8afdabe9fd 100644
Binary files a/packages/frontend/assets/room/objects/mixer/textures/body.png and b/packages/frontend/assets/room/objects/mixer/textures/body.png differ
diff --git a/packages/frontend/src/utility/room/engine.ts b/packages/frontend/src/utility/room/engine.ts
index 4d431054cc..c904f8a0f7 100644
--- a/packages/frontend/src/utility/room/engine.ts
+++ b/packages/frontend/src/utility/room/engine.ts
@@ -311,6 +311,7 @@ export class RoomEngine {
 		this.shadowGenerator1.forceBackFacesOnly = true;
 		this.shadowGenerator1.bias = 0.0001;
 		this.shadowGenerator1.usePercentageCloserFiltering = true;
+		this.shadowGenerator1.filteringQuality = BABYLON.ShadowGenerator.QUALITY_HIGH;
 		//this.shadowGenerator1.useContactHardeningShadow = true;
 
 		const sunLight = new BABYLON.DirectionalLight('sunLight', new BABYLON.Vector3(0.2, -1, -1), this.scene);
diff --git a/packages/frontend/src/utility/room/object-defs.ts b/packages/frontend/src/utility/room/object-defs.ts
index 5326e4a819..2004c42ba3 100644
--- a/packages/frontend/src/utility/room/object-defs.ts
+++ b/packages/frontend/src/utility/room/object-defs.ts
@@ -3,6 +3,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
+import { a4Case } from './objects/a4Case.js';
 import { aircon } from './objects/aircon.js';
 import { aquarium } from './objects/aquarium.js';
 import { banknote } from './objects/banknote.js';
@@ -45,6 +46,7 @@ import { wallShelf } from './objects/wallShelf.js';
 import { woodSoundAbsorbingPanel } from './objects/woodSoundAbsorbingPanel.js';
 
 export const OBJECT_DEFS = [
+	a4Case,
 	aircon,
 	aquarium,
 	banknote,
diff --git a/packages/frontend/src/utility/room/objects/a4Case.ts b/packages/frontend/src/utility/room/objects/a4Case.ts
new file mode 100644
index 0000000000..9ef077ef19
--- /dev/null
+++ b/packages/frontend/src/utility/room/objects/a4Case.ts
@@ -0,0 +1,42 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import * as BABYLON from '@babylonjs/core';
+import { defineObject } from '../engine.js';
+
+export const a4Case = defineObject({
+	id: 'a4Case',
+	name: 'A4 Case',
+	options: {
+		schema: {
+			color: {
+				type: 'color',
+				label: 'Color',
+			},
+		},
+		default: {
+			color: [0.9, 0.9, 0.9],
+		},
+	},
+	placement: 'top',
+	createInstance: ({ options, root }) => {
+		const bodyMesh = root.getChildMeshes().find(m => m.name.includes('__X_BODY__')) as BABYLON.Mesh;
+		const bodyMaterial = bodyMesh.material as BABYLON.PBRMaterial;
+
+		const applyColor = () => {
+			const [r, g, b] = options.color;
+			bodyMaterial.albedoColor = new BABYLON.Color3(r, g, b);
+		};
+
+		applyColor();
+
+		return {
+			onOptionsUpdated: ([k, v]) => {
+				applyColor();
+			},
+			interactions: {},
+		};
+	},
+});