diff --git a/Assets/VRM/Runtime/IO/VRMImporterContext.cs b/Assets/VRM/Runtime/IO/VRMImporterContext.cs
index fdd818bf8..c567c1645 100644
--- a/Assets/VRM/Runtime/IO/VRMImporterContext.cs
+++ b/Assets/VRM/Runtime/IO/VRMImporterContext.cs
@@ -20,7 +20,7 @@ namespace VRM
             }
         }
 
-        IVrm0xSpringBoneRuntime _springBoneRuntime;
+        IVrm0XSpringBoneRuntime _springBoneRuntime;
 
         public VRMImporterContext(
             VRMData data,
@@ -28,12 +28,12 @@ namespace VRM
             ITextureDeserializer textureDeserializer = null,
             IMaterialDescriptorGenerator materialGenerator = null,
             ImporterContextSettings settings = null,
-            IVrm0xSpringBoneRuntime springboneRuntime = null)
+            IVrm0XSpringBoneRuntime springboneRuntime = null)
             : base(data.Data, externalObjectMap, textureDeserializer, materialGenerator ?? VrmMaterialDescriptorGeneratorUtility.GetValidVrmMaterialDescriptorGenerator(data.VrmExtension), settings ?? new ImporterContextSettings(false))
         {
             _data = data;
             TextureDescriptorGenerator = new VrmTextureDescriptorGenerator(Data, VRM);
-            _springBoneRuntime = springboneRuntime ?? new Vrm0xSpringBoneDefaultRuntime();
+            _springBoneRuntime = springboneRuntime ?? new Vrm0XSpringBoneDefaultRuntime();
         }
 
         #region OnLoad
diff --git a/Assets/VRM/Runtime/IO/VrmUtility.cs b/Assets/VRM/Runtime/IO/VrmUtility.cs
index d1385ce7f..a5a28274f 100644
--- a/Assets/VRM/Runtime/IO/VrmUtility.cs
+++ b/Assets/VRM/Runtime/IO/VrmUtility.cs
@@ -74,7 +74,7 @@ namespace VRM
             MetaCallback metaCallback = null,
             ITextureDeserializer textureDeserializer = null,
             bool loadAnimation = false,
-            IVrm0xSpringBoneRuntime springboneRuntime = null
+            IVrm0XSpringBoneRuntime springboneRuntime = null
             )
         {
             if (bytes == null)
diff --git a/Assets/VRM/Runtime/SpringBone/IVrm0xSpringBoneRuntime.cs b/Assets/VRM/Runtime/SpringBone/IVrm0XSpringBoneRuntime.cs
similarity index 78%
rename from Assets/VRM/Runtime/SpringBone/IVrm0xSpringBoneRuntime.cs
rename to Assets/VRM/Runtime/SpringBone/IVrm0XSpringBoneRuntime.cs
index 0cd583cc2..e8038efe8 100644
--- a/Assets/VRM/Runtime/SpringBone/IVrm0xSpringBoneRuntime.cs
+++ b/Assets/VRM/Runtime/SpringBone/IVrm0XSpringBoneRuntime.cs
@@ -4,7 +4,7 @@ using UnityEngine;
 
 namespace VRM
 {
-    public interface IVrm0xSpringBoneRuntime
+    public interface IVrm0XSpringBoneRuntime
     {
         public Task InitializeAsync(GameObject vrm, IAwaitCaller awaitCaller);
     }
diff --git a/Assets/VRM/Runtime/SpringBone/IVrm0xSpringBoneRuntime.cs.meta b/Assets/VRM/Runtime/SpringBone/IVrm0XSpringBoneRuntime.cs.meta
similarity index 100%
rename from Assets/VRM/Runtime/SpringBone/IVrm0xSpringBoneRuntime.cs.meta
rename to Assets/VRM/Runtime/SpringBone/IVrm0XSpringBoneRuntime.cs.meta
diff --git a/Assets/VRM/Runtime/SpringBone/Jobs/Vrm0xFastSpringBoneRuntime.cs b/Assets/VRM/Runtime/SpringBone/Jobs/Vrm0XFastSpringBoneRuntime.cs
similarity index 95%
rename from Assets/VRM/Runtime/SpringBone/Jobs/Vrm0xFastSpringBoneRuntime.cs
rename to Assets/VRM/Runtime/SpringBone/Jobs/Vrm0XFastSpringBoneRuntime.cs
index 765e7433f..4d8fcc1c4 100644
--- a/Assets/VRM/Runtime/SpringBone/Jobs/Vrm0xFastSpringBoneRuntime.cs
+++ b/Assets/VRM/Runtime/SpringBone/Jobs/Vrm0XFastSpringBoneRuntime.cs
@@ -14,7 +14,7 @@ namespace VRM
     /// FastSpringBoneService に登録します。
     /// FastSpringBoneService.LateUpdate[DefaultExecutionOrder(11000)] で動作します。
     /// </summary>
-    public class Vrm0xFastSpringboneRuntime : IVrm0xSpringBoneRuntime
+    public class Vrm0XFastSpringboneRuntime : IVrm0XSpringBoneRuntime
     {
         public async Task InitializeAsync(GameObject vrm, IAwaitCaller awaitCaller)
         {
diff --git a/Assets/VRM/Runtime/SpringBone/Jobs/Vrm0xFastSpringBoneRuntime.cs.meta b/Assets/VRM/Runtime/SpringBone/Jobs/Vrm0XFastSpringBoneRuntime.cs.meta
similarity index 100%
rename from Assets/VRM/Runtime/SpringBone/Jobs/Vrm0xFastSpringBoneRuntime.cs.meta
rename to Assets/VRM/Runtime/SpringBone/Jobs/Vrm0XFastSpringBoneRuntime.cs.meta
diff --git a/Assets/VRM/Runtime/SpringBone/Vrm0xSpringBoneDefaultRuntime.cs b/Assets/VRM/Runtime/SpringBone/Vrm0XSpringBoneDefaultRuntime.cs
similarity index 91%
rename from Assets/VRM/Runtime/SpringBone/Vrm0xSpringBoneDefaultRuntime.cs
rename to Assets/VRM/Runtime/SpringBone/Vrm0XSpringBoneDefaultRuntime.cs
index 57e4acc05..dabe8adb7 100644
--- a/Assets/VRM/Runtime/SpringBone/Vrm0xSpringBoneDefaultRuntime.cs
+++ b/Assets/VRM/Runtime/SpringBone/Vrm0XSpringBoneDefaultRuntime.cs
@@ -11,7 +11,7 @@ namespace VRM
     /// 
     /// により、各VRMSpringBoneが自力で LateUpdate に動作します。
     /// </summary>
-    public class Vrm0xSpringBoneDefaultRuntime : IVrm0xSpringBoneRuntime
+    public class Vrm0XSpringBoneDefaultRuntime : IVrm0XSpringBoneRuntime
     {
         public async Task InitializeAsync(GameObject vrm, IAwaitCaller awaitCaller)
         {
diff --git a/Assets/VRM/Runtime/SpringBone/Vrm0xSpringBoneDefaultRuntime.cs.meta b/Assets/VRM/Runtime/SpringBone/Vrm0XSpringBoneDefaultRuntime.cs.meta
similarity index 100%
rename from Assets/VRM/Runtime/SpringBone/Vrm0xSpringBoneDefaultRuntime.cs.meta
rename to Assets/VRM/Runtime/SpringBone/Vrm0XSpringBoneDefaultRuntime.cs.meta
diff --git a/Assets/VRM_Samples/SimpleViewer/ViewerUI.cs b/Assets/VRM_Samples/SimpleViewer/ViewerUI.cs
index b70f2f6c3..78024b8fc 100644
--- a/Assets/VRM_Samples/SimpleViewer/ViewerUI.cs
+++ b/Assets/VRM_Samples/SimpleViewer/ViewerUI.cs
@@ -395,7 +395,7 @@ namespace VRM.SimpleViewer
             var instance = await VrmUtility.LoadBytesAsync(path, bytes, GetIAwaitCaller(m_useAsync.isOn),
                 materialCallback, metaCallback,
                 loadAnimation: m_loadAnimation.isOn,
-                springboneRuntime: m_useFastSpringBone.isOn ? new Vrm0xFastSpringboneRuntime() : new Vrm0xSpringBoneDefaultRuntime()
+                springboneRuntime: m_useFastSpringBone.isOn ? new Vrm0XFastSpringboneRuntime() : new Vrm0XSpringBoneDefaultRuntime()
                 );
 
             instance.EnableUpdateWhenOffscreen();