diff --git a/Assets/UniGLTF/Samples/ScreenSpace/UniGLTF.Samples.ScreenSpace.asmdef b/Assets/UniGLTF/Samples/ScreenSpace/UniGLTF.Samples.ScreenSpace.asmdef
new file mode 100644
index 0000000000..864265c647
--- /dev/null
+++ b/Assets/UniGLTF/Samples/ScreenSpace/UniGLTF.Samples.ScreenSpace.asmdef
@@ -0,0 +1,15 @@
+{
+    "name": "UniGLTF.Samples.ScreenSpace",
+    "references": [
+        "GUID:8d76e605759c3f64a957d63ef96ada7c"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": [],
+    "versionDefines": [],
+    "noEngineReferences": false
+}
\ No newline at end of file
diff --git a/Assets/UniGLTF/Samples/ScreenSpace/UniGLTF.Samples.ScreenSpace.asmdef.meta b/Assets/UniGLTF/Samples/ScreenSpace/UniGLTF.Samples.ScreenSpace.asmdef.meta
new file mode 100644
index 0000000000..a171280cf3
--- /dev/null
+++ b/Assets/UniGLTF/Samples/ScreenSpace/UniGLTF.Samples.ScreenSpace.asmdef.meta
@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: b7fdb0325c3f0a9449a1b286964a4e0f
+AssemblyDefinitionImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/VRM/Samples/AnimationBridgeSample/VRM.Samples.AnimationBridgeSample.asmdef b/Assets/VRM/Samples/AnimationBridgeSample/VRM.Samples.AnimationBridgeSample.asmdef
new file mode 100644
index 0000000000..cc52084a91
--- /dev/null
+++ b/Assets/VRM/Samples/AnimationBridgeSample/VRM.Samples.AnimationBridgeSample.asmdef
@@ -0,0 +1,15 @@
+{
+    "name": "VRM.Samples.AnimationBridgeSample",
+    "references": [
+        "GUID:05dd262a0c0a2f841b8252c8c3815582"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": [],
+    "versionDefines": [],
+    "noEngineReferences": false
+}
\ No newline at end of file
diff --git a/Assets/VRM/Samples/AnimationBridgeSample/VRM.Samples.AnimationBridgeSample.asmdef.meta b/Assets/VRM/Samples/AnimationBridgeSample/VRM.Samples.AnimationBridgeSample.asmdef.meta
new file mode 100644
index 0000000000..0dace42eb3
--- /dev/null
+++ b/Assets/VRM/Samples/AnimationBridgeSample/VRM.Samples.AnimationBridgeSample.asmdef.meta
@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 6b040b1abc5395c4982c9a4d5c3dd916
+AssemblyDefinitionImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/VRM/Samples/FirstPersonSample/VRM.Samples.FirstPersonSample.asmdef b/Assets/VRM/Samples/FirstPersonSample/VRM.Samples.FirstPersonSample.asmdef
new file mode 100644
index 0000000000..fd74fd3175
--- /dev/null
+++ b/Assets/VRM/Samples/FirstPersonSample/VRM.Samples.FirstPersonSample.asmdef
@@ -0,0 +1,18 @@
+{
+    "name": "VRM.Samples.FirstPersonSample",
+    "references": [
+        "GUID:da3e51d19d51a544fa14d43fee843098",
+        "GUID:b7aa47b240b57de44a4b2021c143c9bf",
+        "GUID:8d76e605759c3f64a957d63ef96ada7c",
+        "GUID:05dd262a0c0a2f841b8252c8c3815582"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": [],
+    "versionDefines": [],
+    "noEngineReferences": false
+}
\ No newline at end of file
diff --git a/Assets/VRM/Samples/FirstPersonSample/VRM.Samples.FirstPersonSample.asmdef.meta b/Assets/VRM/Samples/FirstPersonSample/VRM.Samples.FirstPersonSample.asmdef.meta
new file mode 100644
index 0000000000..75881b15ad
--- /dev/null
+++ b/Assets/VRM/Samples/FirstPersonSample/VRM.Samples.FirstPersonSample.asmdef.meta
@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 48e0f44c1c000a94084ebda1628046d0
+AssemblyDefinitionImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/VRM/Samples/RuntimeExporterSample/VRM.Samples.RuntimeExporterSample.asmdef b/Assets/VRM/Samples/RuntimeExporterSample/VRM.Samples.RuntimeExporterSample.asmdef
new file mode 100644
index 0000000000..d4c423ecd7
--- /dev/null
+++ b/Assets/VRM/Samples/RuntimeExporterSample/VRM.Samples.RuntimeExporterSample.asmdef
@@ -0,0 +1,17 @@
+{
+    "name": "VRM.Samples.RuntimeExporterSample",
+    "references": [
+        "GUID:da3e51d19d51a544fa14d43fee843098",
+        "GUID:8d76e605759c3f64a957d63ef96ada7c",
+        "GUID:05dd262a0c0a2f841b8252c8c3815582"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": [],
+    "versionDefines": [],
+    "noEngineReferences": false
+}
\ No newline at end of file
diff --git a/Assets/VRM/Samples/RuntimeExporterSample/VRM.Samples.RuntimeExporterSample.asmdef.meta b/Assets/VRM/Samples/RuntimeExporterSample/VRM.Samples.RuntimeExporterSample.asmdef.meta
new file mode 100644
index 0000000000..dc276a3481
--- /dev/null
+++ b/Assets/VRM/Samples/RuntimeExporterSample/VRM.Samples.RuntimeExporterSample.asmdef.meta
@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 1309c81c467ec1c479b3f19a8b0f7ad4
+AssemblyDefinitionImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/VRM/Samples/SimpleViewer/VRM.Samples.SimpleViewer.asmdef b/Assets/VRM/Samples/SimpleViewer/VRM.Samples.SimpleViewer.asmdef
new file mode 100644
index 0000000000..34e7e556d4
--- /dev/null
+++ b/Assets/VRM/Samples/SimpleViewer/VRM.Samples.SimpleViewer.asmdef
@@ -0,0 +1,18 @@
+{
+    "name": "VRM.Samples.SimpleViewer",
+    "references": [
+        "GUID:da3e51d19d51a544fa14d43fee843098",
+        "GUID:b7aa47b240b57de44a4b2021c143c9bf",
+        "GUID:8d76e605759c3f64a957d63ef96ada7c",
+        "GUID:05dd262a0c0a2f841b8252c8c3815582"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": [],
+    "versionDefines": [],
+    "noEngineReferences": false
+}
\ No newline at end of file
diff --git a/Assets/VRM/Samples/SimpleViewer/VRM.Samples.SimpleViewer.asmdef.meta b/Assets/VRM/Samples/SimpleViewer/VRM.Samples.SimpleViewer.asmdef.meta
new file mode 100644
index 0000000000..2e4a4a5644
--- /dev/null
+++ b/Assets/VRM/Samples/SimpleViewer/VRM.Samples.SimpleViewer.asmdef.meta
@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 42e9a7b6394cf484fb209ac80e611df2
+AssemblyDefinitionImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/VRM10/Editor/EditorTool/VRM10BoneSelectorEditorTool.cs b/Assets/VRM10/Editor/EditorTool/VRM10BoneSelectorEditorTool.cs
index 410a382a1e..77e5827995 100644
--- a/Assets/VRM10/Editor/EditorTool/VRM10BoneSelectorEditorTool.cs
+++ b/Assets/VRM10/Editor/EditorTool/VRM10BoneSelectorEditorTool.cs
@@ -3,6 +3,11 @@
 using UnityEditor.EditorTools;
 using UniGLTF;
 
+#if UNITY_2021_OR_NEWER
+#else
+using ToolManager = UnityEditor.EditorTools.EditorTools;
+#endif
+
 namespace UniVRM10
 {
     /// <summary>
@@ -27,7 +32,7 @@ public override GUIContent toolbarIcon
         BoneSelector _impl;
         void OnEnable()
         {
-            EditorTools.activeToolChanged += ActiveToolDidChange;
+            ToolManager.activeToolChanged += ActiveToolDidChange;
             if (SceneView.lastActiveSceneView?.camera)
             {
             }
@@ -35,7 +40,7 @@ void OnEnable()
 
         void OnDisable()
         {
-            EditorTools.activeToolChanged -= ActiveToolDidChange;
+            ToolManager.activeToolChanged -= ActiveToolDidChange;
             if (_impl != null)
             {
                 _impl.Dispose();
@@ -45,7 +50,7 @@ void OnDisable()
 
         void ActiveToolDidChange()
         {
-            if (EditorTools.IsActiveTool(this))
+            if (ToolManager.IsActiveTool(this))
             {
             }
             else
diff --git a/Assets/VRM10/Editor/EditorTool/VRM10ExpressionEditorTool.cs b/Assets/VRM10/Editor/EditorTool/VRM10ExpressionEditorTool.cs
index 5139280ce2..15285914d0 100644
--- a/Assets/VRM10/Editor/EditorTool/VRM10ExpressionEditorTool.cs
+++ b/Assets/VRM10/Editor/EditorTool/VRM10ExpressionEditorTool.cs
@@ -4,6 +4,11 @@
 using UnityEditor.EditorTools;
 using UnityEngine;
 
+#if UNITY_2021_OR_NEWER
+#else
+using ToolManager = UnityEditor.EditorTools.EditorTools;
+#endif
+
 namespace UniVRM10
 {
     [EditorTool("vrm-1.0/Expression", typeof(UniVRM10.Vrm10Instance))]
@@ -24,17 +29,17 @@ public override GUIContent toolbarIcon
 
         void OnEnable()
         {
-            EditorTools.activeToolChanged += ActiveToolDidChange;
+            ToolManager.activeToolChanged += ActiveToolDidChange;
         }
 
         void OnDisable()
         {
-            EditorTools.activeToolChanged -= ActiveToolDidChange;
+            ToolManager.activeToolChanged -= ActiveToolDidChange;
         }
 
         void ActiveToolDidChange()
         {
-            if (!EditorTools.IsActiveTool(this))
+            if (!ToolManager.IsActiveTool(this))
             {
                 return;
             }
diff --git a/Assets/VRM10/Editor/EditorTool/VRM10LookAtEditorTool.cs b/Assets/VRM10/Editor/EditorTool/VRM10LookAtEditorTool.cs
index 19a9ea5b47..854f6845b5 100644
--- a/Assets/VRM10/Editor/EditorTool/VRM10LookAtEditorTool.cs
+++ b/Assets/VRM10/Editor/EditorTool/VRM10LookAtEditorTool.cs
@@ -2,6 +2,11 @@
 using UnityEditor;
 using UnityEditor.EditorTools;
 
+#if UNITY_2021_OR_NEWER
+#else
+using ToolManager = UnityEditor.EditorTools.EditorTools;
+#endif
+
 
 namespace UniVRM10
 {
@@ -23,17 +28,17 @@ public override GUIContent toolbarIcon
 
         void OnEnable()
         {
-            EditorTools.activeToolChanged += ActiveToolDidChange;
+            ToolManager.activeToolChanged += ActiveToolDidChange;
         }
 
         void OnDisable()
         {
-            EditorTools.activeToolChanged -= ActiveToolDidChange;
+            ToolManager.activeToolChanged -= ActiveToolDidChange;
         }
 
         void ActiveToolDidChange()
         {
-            if (!EditorTools.IsActiveTool(this))
+            if (!ToolManager.IsActiveTool(this))
             {
                 return;
             }
diff --git a/Assets/VRM10/Samples/VRM10FirstPersonSample/VRM10.Samples.VRM10FirstPersonSample.asmdef b/Assets/VRM10/Samples/VRM10FirstPersonSample/VRM10.Samples.VRM10FirstPersonSample.asmdef
new file mode 100644
index 0000000000..032a31c0c7
--- /dev/null
+++ b/Assets/VRM10/Samples/VRM10FirstPersonSample/VRM10.Samples.VRM10FirstPersonSample.asmdef
@@ -0,0 +1,18 @@
+{
+    "name": "VRM10.Samples.VRM10FirstPersonSample",
+    "references": [
+        "GUID:da3e51d19d51a544fa14d43fee843098",
+        "GUID:b7aa47b240b57de44a4b2021c143c9bf",
+        "GUID:8d76e605759c3f64a957d63ef96ada7c",
+        "GUID:e47c917724578cc43b5506c17a27e9a0"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": [],
+    "versionDefines": [],
+    "noEngineReferences": false
+}
\ No newline at end of file
diff --git a/Assets/VRM10/Samples/VRM10FirstPersonSample/VRM10.Samples.VRM10FirstPersonSample.asmdef.meta b/Assets/VRM10/Samples/VRM10FirstPersonSample/VRM10.Samples.VRM10FirstPersonSample.asmdef.meta
new file mode 100644
index 0000000000..ed7cd1b380
--- /dev/null
+++ b/Assets/VRM10/Samples/VRM10FirstPersonSample/VRM10.Samples.VRM10FirstPersonSample.asmdef.meta
@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: c408845854bb97b438c53ae441fbdead
+AssemblyDefinitionImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/VRM10/Samples/VRM10Viewer/VRM10.Samples.VRM10Viewer.asmdef b/Assets/VRM10/Samples/VRM10Viewer/VRM10.Samples.VRM10Viewer.asmdef
new file mode 100644
index 0000000000..1082f824ba
--- /dev/null
+++ b/Assets/VRM10/Samples/VRM10Viewer/VRM10.Samples.VRM10Viewer.asmdef
@@ -0,0 +1,18 @@
+{
+    "name": "VRM10.Samples.VRM10Viewer",
+    "references": [
+        "GUID:b7aa47b240b57de44a4b2021c143c9bf",
+        "GUID:da3e51d19d51a544fa14d43fee843098",
+        "GUID:8d76e605759c3f64a957d63ef96ada7c",
+        "GUID:e47c917724578cc43b5506c17a27e9a0"
+    ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
+    "allowUnsafeCode": false,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": [],
+    "versionDefines": [],
+    "noEngineReferences": false
+}
\ No newline at end of file
diff --git a/Assets/VRM10/Samples/VRM10Viewer/VRM10.Samples.VRM10Viewer.asmdef.meta b/Assets/VRM10/Samples/VRM10Viewer/VRM10.Samples.VRM10Viewer.asmdef.meta
new file mode 100644
index 0000000000..b3dca9964f
--- /dev/null
+++ b/Assets/VRM10/Samples/VRM10Viewer/VRM10.Samples.VRM10Viewer.asmdef.meta
@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 2d70a88b57fd51e47885e80f0ad2f884
+AssemblyDefinitionImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: