diff --git a/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10FastSpringboneRuntime.cs b/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10FastSpringboneRuntime.cs
index d02e6ec97..11d70268c 100644
--- a/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10FastSpringboneRuntime.cs
+++ b/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10FastSpringboneRuntime.cs
@@ -14,7 +14,7 @@ namespace UniVRM10
     public class Vrm10FastSpringboneRuntime : IVrm10SpringBoneRuntime
     {
         private Vrm10Instance m_instance;
-        private readonly FastSpringBones.FastSpringBoneService m_fastSpringBoneService = FastSpringBones.FastSpringBoneService.Instance;
+        private FastSpringBones.FastSpringBoneService m_fastSpringBoneService;
         private FastSpringBoneBuffer m_fastSpringBoneBuffer;
 
         public Vector3 ExternalForce
@@ -32,6 +32,7 @@ namespace UniVRM10
 
         public async Task InitializeAsync(Vrm10Instance instance, IAwaitCaller awaitCaller)
         {
+            m_fastSpringBoneService = FastSpringBones.FastSpringBoneService.Instance;
             m_instance = instance;
 
             // NOTE: FastSpringBoneService は UnitTest などでは動作しない
diff --git a/Assets/VRM10/Runtime/IO/Vrm10Importer.cs b/Assets/VRM10/Runtime/IO/Vrm10Importer.cs
index 8347dbb11..be77bb089 100644
--- a/Assets/VRM10/Runtime/IO/Vrm10Importer.cs
+++ b/Assets/VRM10/Runtime/IO/Vrm10Importer.cs
@@ -273,8 +273,12 @@ namespace UniVRM10
             if (UniGLTF.Extensions.VRMC_springBone.GltfDeserializer.TryGet(Data.GLTF.extensions, out UniGLTF.Extensions.VRMC_springBone.VRMC_springBone springBone))
             {
                 await LoadSpringBoneAsync(awaitCaller, controller, springBone);
-                // Vrm10Runtime で初期化していたが、 async にするためこちらに移動 v0.127
-                await m_springboneRuntime.InitializeAsync(controller, awaitCaller);
+                if (Application.isPlaying)
+                {
+                    // EditorImport では呼ばない
+                    // Vrm10Runtime で初期化していたが、 async にするためこちらに移動 v0.127
+                    await m_springboneRuntime.InitializeAsync(controller, awaitCaller);
+                }
             }
             // constraint
             await LoadConstraintAsync(awaitCaller, controller);