diff --git a/Assets/UniGLTF/Runtime/Extensions/ArrayExtensions.cs b/Assets/UniGLTF/Runtime/Extensions/ArrayExtensions.cs
index 42d15c547..6547f93c8 100644
--- a/Assets/UniGLTF/Runtime/Extensions/ArrayExtensions.cs
+++ b/Assets/UniGLTF/Runtime/Extensions/ArrayExtensions.cs
@@ -2,7 +2,7 @@
 using System.Linq;
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
-
+using Unity.Collections;
 
 namespace UniGLTF
 {
@@ -102,7 +102,7 @@ namespace UniGLTF
 
     public static class ListExtensions
     {
-        public static void Assign<T>(this List<T> dst, T[] src, Func<T, T> pred)
+        public static void Assign<T>(this List<T> dst, NativeArray<T> src, Func<T, T> pred) where T : struct
         {
             dst.Capacity = src.Length;
             dst.AddRange(src.Select(pred));
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/AnimationIO/AnimationImporterUtil.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/AnimationIO/AnimationImporterUtil.cs
index 7d4f16239..8c38c23a3 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/AnimationIO/AnimationImporterUtil.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/AnimationIO/AnimationImporterUtil.cs
@@ -208,8 +208,8 @@ namespace UniGLTF
                                 clip,
                                 relativePath,
                                 new string[] { "localPosition.x", "localPosition.y", "localPosition.z" },
-                                input,
-                                output,
+                                input.ToArray(),
+                                output.ToArray(),
                                 sampler.interpolation,
                                 typeof(Transform),
                                 (values, last) =>
@@ -231,8 +231,8 @@ namespace UniGLTF
                                 clip,
                                 relativePath,
                                 new string[] { "localRotation.x", "localRotation.y", "localRotation.z", "localRotation.w" },
-                                input,
-                                output,
+                                input.ToArray(),
+                                output.ToArray(),
                                 sampler.interpolation,
                                 typeof(Transform),
                                 (values, last) =>
@@ -257,8 +257,8 @@ namespace UniGLTF
                                 clip,
                                 relativePath,
                                 new string[] { "localScale.x", "localScale.y", "localScale.z" },
-                                input,
-                                output,
+                                input.ToArray(),
+                                output.ToArray(),
                                 sampler.interpolation,
                                 typeof(Transform),
                                 (values, last) => values);
@@ -289,8 +289,8 @@ namespace UniGLTF
                                 clip,
                                 relativePath,
                                 keyNames,
-                                input,
-                                output,
+                                input.ToArray(),
+                                output.ToArray(),
                                 sampler.interpolation,
                                 typeof(SkinnedMeshRenderer),
                                 (values, last) =>
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs
index 19d720102..eeccc501e 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.InteropServices;
+using Unity.Collections;
 
 namespace UniGLTF
 {
@@ -9,7 +10,7 @@ namespace UniGLTF
     /// * JSON is parsed but not validated as glTF
     /// * For glb, bin chunks are already available
     /// </summary>
-    public sealed class GltfData
+    public sealed class GltfData : IDisposable
     {
         /// <summary>
         /// Source file path.
@@ -43,21 +44,7 @@ namespace UniGLTF
         /// > This chunk MUST be the second chunk of the Binary glTF asset
         /// </summary>
         /// <returns></returns>
-        public ArraySegment<byte> Bin
-        {
-            get
-            {
-                if (Chunks == null)
-                {
-                    return default;
-                }
-                if (Chunks.Count < 2)
-                {
-                    return default;
-                }
-                return Chunks[1].Bytes;
-            }
-        }
+        public readonly NativeArray<byte> Bin;
 
         /// <summary>
         /// Migration Flags used by ImporterContext
@@ -74,7 +61,7 @@ namespace UniGLTF
         /// uri = 相対パス。File.ReadAllBytes
         /// </summary>
         /// <returns></returns>
-        Dictionary<string, ArraySegment<byte>> _UriCache = new Dictionary<string, ArraySegment<byte>>();
+        Dictionary<string, NativeArray<byte>> _UriCache = new Dictionary<string, NativeArray<byte>>();
 
         public GltfData(string targetPath, string json, glTF gltf, IReadOnlyList<GlbChunk> chunks, IStorage storage, MigrationFlags migrationFlags)
         {
@@ -84,6 +71,14 @@ namespace UniGLTF
             Chunks = chunks;
             _storage = storage;
             MigrationFlags = migrationFlags;
+
+            if (Chunks != null)
+            {
+                if (Chunks.Count >= 2)
+                {
+                    Bin = CreateNativeArray(Chunks[1].Bytes);
+                }
+            }
         }
 
         public static GltfData CreateFromExportForTest(ExportingGltfData data)
@@ -107,14 +102,14 @@ namespace UniGLTF
             );
         }
 
-        ArraySegment<Byte> GetBytesFromUri(string uri)
+        NativeArray<Byte> GetBytesFromUri(string uri)
         {
             if (string.IsNullOrEmpty(uri))
             {
                 throw new ArgumentNullException();
             }
 
-            if (_UriCache.TryGetValue(uri, out ArraySegment<byte> data))
+            if (_UriCache.TryGetValue(uri, out NativeArray<byte> data))
             {
                 // return cache
                 return data;
@@ -122,20 +117,20 @@ namespace UniGLTF
 
             if (uri.StartsWith("data:", StringComparison.Ordinal))
             {
-                data = new ArraySegment<byte>(UriByteBuffer.ReadEmbedded(uri));
+                data = CreateNativeArray(UriByteBuffer.ReadEmbedded(uri));
             }
             else
             {
-                data = _storage.Get(uri);
+                data = CreateNativeArray(_storage.Get(uri));
             }
             _UriCache.Add(uri, data);
             return data;
         }
 
-        public ArraySegment<Byte> GetBytesFromBuffer(int bufferIndex)
+        public NativeArray<Byte> GetBytesFromBuffer(int bufferIndex)
         {
             var buffer = GLTF.buffers[bufferIndex];
-            if (bufferIndex == 0 && Bin.Array != null)
+            if (bufferIndex == 0 && Bin.IsCreated)
             {
                 // https://www.khronos.org/registry/glTF/specs/2.0/glTF-2.0.html#glb-stored-buffer
                 return Bin;
@@ -146,23 +141,20 @@ namespace UniGLTF
             }
         }
 
-        public ArraySegment<Byte> GetBytesFromBufferView(int bufferView)
+        public NativeArray<Byte> GetBytesFromBufferView(int bufferView)
         {
             var view = GLTF.bufferViews[bufferView];
             var segment = GetBytesFromBuffer(view.buffer);
-            return new ArraySegment<byte>(segment.Array, segment.Offset + view.byteOffset, view.byteLength);
+            return segment.GetSubArray(view.byteOffset, view.byteLength);
         }
 
-        T[] GetTypedFromBufferView<T>(int count, int byteOffset, glTFBufferView view) where T : struct
+        NativeArray<T> GetTypedFromBufferView<T>(int count, int byteOffset, glTFBufferView view) where T : struct
         {
             var segment = GetBytesFromBuffer(view.buffer);
-            var attrib = new T[count];
-            var bytes = new ArraySegment<Byte>(segment.Array, segment.Offset + view.byteOffset + byteOffset, count * Marshal.SizeOf<T>());
-            SafeMarshalCopy.CopyBytesToArray(bytes, attrib);
-            return attrib;
+            return segment.GetSubArray(view.byteOffset + byteOffset, count * Marshal.SizeOf<T>()).Reinterpret<T>(1);
         }
 
-        T[] GetTypedFromAccessor<T>(glTFAccessor accessor, glTFBufferView view) where T : struct
+        NativeArray<T> GetTypedFromAccessor<T>(glTFAccessor accessor, glTFBufferView view) where T : struct
         {
             return GetTypedFromBufferView<T>(accessor.count, accessor.byteOffset, view);
         }
@@ -247,15 +239,15 @@ namespace UniGLTF
             return indices;
         }
 
-        public T[] GetArrayFromAccessor<T>(int accessorIndex) where T : struct
+        public NativeArray<T> GetArrayFromAccessor<T>(int accessorIndex) where T : struct
         {
             var vertexAccessor = GLTF.accessors[accessorIndex];
 
-            if (vertexAccessor.count <= 0) return new T[] { };
+            if (vertexAccessor.count <= 0) return CreateNativeArray<T>(0);
 
             var result = (vertexAccessor.bufferView != -1)
                 ? GetTypedFromAccessor<T>(vertexAccessor, GLTF.bufferViews[vertexAccessor.bufferView])
-                : new T[vertexAccessor.count]
+                : CreateNativeArray<T>(vertexAccessor.count)
                 ;
 
             var sparse = vertexAccessor.sparse;
@@ -275,27 +267,24 @@ namespace UniGLTF
             return result;
         }
 
-        public float[] FlatternFloatArrayFromAccessor(int accessorIndex)
+        public NativeArray<float> FlatternFloatArrayFromAccessor(int accessorIndex)
         {
             var vertexAccessor = GLTF.accessors[accessorIndex];
 
-            if (vertexAccessor.count <= 0) return new float[] { };
+            if (vertexAccessor.count <= 0) return CreateNativeArray<float>(0);
 
             var bufferCount = vertexAccessor.count * vertexAccessor.TypeCount;
 
-            float[] result = null;
+            NativeArray<float> result = default;
             if (vertexAccessor.bufferView != -1)
             {
-                var attrib = new float[vertexAccessor.count * vertexAccessor.TypeCount];
                 var view = GLTF.bufferViews[vertexAccessor.bufferView];
                 var segment = GetBytesFromBuffer(view.buffer);
-                var bytes = new ArraySegment<Byte>(segment.Array, segment.Offset + view.byteOffset + vertexAccessor.byteOffset, vertexAccessor.count * 4 * vertexAccessor.TypeCount);
-                SafeMarshalCopy.CopyBytesToArray(bytes, attrib);
-                result = attrib;
+                result = segment.GetSubArray(view.byteOffset + vertexAccessor.byteOffset, vertexAccessor.count * 4 * vertexAccessor.TypeCount).Reinterpret<float>(1);
             }
             else
             {
-                result = new float[bufferCount];
+                result = CreateNativeArray<float>(bufferCount);
             }
 
             var sparse = vertexAccessor.sparse;
@@ -315,7 +304,7 @@ namespace UniGLTF
             return result;
         }
 
-        public (ArraySegment<byte> binary, string mimeType)? GetBytesFromImage(int imageIndex)
+        public (NativeArray<byte> binary, string mimeType)? GetBytesFromImage(int imageIndex)
         {
             if (imageIndex < 0 || imageIndex >= GLTF.images.Count) return default;
 
@@ -373,5 +362,46 @@ namespace UniGLTF
 
             return false;
         }
+
+        /// <summary>
+        /// NativeArrayを新規作成し、Dispose管理する。
+        /// 個別にDisposeする必要が無い。
+        /// </summary>
+        /// <param name="size"></param>
+        /// <typeparam name="T"></typeparam>
+        /// <returns></returns>
+        public NativeArray<T> CreateNativeArray<T>(int size) where T : struct
+        {
+            var array = new NativeArray<T>(size, Allocator.Persistent);
+            m_disposables.Add(array);
+            return array;
+        }
+
+        NativeArray<T> CreateNativeArray<T>(ArraySegment<T> data) where T : struct
+        {
+            var array = CreateNativeArray<T>(data.Count);
+            // TODO: remove ToArray
+            array.CopyFrom(data.ToArray());
+            return array;
+        }
+
+        NativeArray<T> CreateNativeArray<T>(T[] data) where T : struct
+        {
+            var array = CreateNativeArray<T>(data.Length);
+            array.CopyFrom(data);
+            return array;
+        }
+
+        List<IDisposable> m_disposables = new List<IDisposable>();
+
+        public void Dispose()
+        {
+            foreach (var disposable in m_disposables)
+            {
+                disposable.Dispose();
+            }
+            m_disposables.Clear();
+            _UriCache.Clear();
+        }
     }
 }
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs
index 7d3f514eb..5cb3a0dfe 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs
@@ -330,6 +330,9 @@ namespace UniGLTF
             AnimationClipFactory?.Dispose();
             MaterialFactory?.Dispose();
             TextureFactory?.Dispose();
+
+            // OK ?
+            Data.Dispose();
         }
 
         /// <summary>
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshContext.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshContext.cs
index 54bc2ba8b..b1507791a 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshContext.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/MeshContext.cs
@@ -142,7 +142,7 @@ namespace UniGLTF
                 for (var i = 0; i < positions.Length; ++i)
                 {
                     var position = inverter.InvertVector3(positions[i]);
-                    var normal = normals != null ? inverter.InvertVector3(normals[i]) : Vector3.zero;
+                    var normal = normals != null ? inverter.InvertVector3(normals.Value[i]) : Vector3.zero;
 
                     var texCoord0 = Vector2.zero;
                     if (texCoords0 != null)
@@ -151,20 +151,20 @@ namespace UniGLTF
                         {
 #pragma warning disable 0612
                             // backward compatibility
-                            texCoord0 = texCoords0[i].ReverseY();
+                            texCoord0 = texCoords0.Value[i].ReverseY();
 #pragma warning restore 0612
                         }
                         else
                         {
-                            texCoord0 = texCoords0[i].ReverseUV();
+                            texCoord0 = texCoords0.Value[i].ReverseUV();
                         }
                     }
 
-                    var texCoord1 = texCoords1 != null ? texCoords1[i].ReverseUV() : Vector2.zero;
+                    var texCoord1 = texCoords1 != null ? texCoords1.Value[i].ReverseUV() : Vector2.zero;
                     var joints = jointsGetter?.Invoke(i) ?? (0, 0, 0, 0);
                     var weights = weightsGetter != null ? NormalizeBoneWeight(weightsGetter(i)) : (0, 0, 0, 0);
 
-                    var color = colors != null ? colors[i] : Color.white;
+                    var color = colors != null ? colors.Value[i] : Color.white;
                     _vertices.Add(
                         new MeshVertex(
                             position,
@@ -285,24 +285,24 @@ namespace UniGLTF
                 for (var i = 0; i < positions.Length; ++i)
                 {
                     var position = inverter.InvertVector3(positions[i]);
-                    var normal = normals != null ? inverter.InvertVector3(normals[i]) : Vector3.zero;
+                    var normal = normals != null ? inverter.InvertVector3(normals.Value[i]) : Vector3.zero;
                     var texCoord0 = Vector2.zero;
                     if (texCoords0 != null)
                     {
                         if (data.GLTF.IsGeneratedUniGLTFAndOlder(1, 16))
                         {
 #pragma warning disable 0612
-                            texCoord0 = texCoords0[i].ReverseY();
+                            texCoord0 = texCoords0.Value[i].ReverseY();
 #pragma warning restore 0612
                         }
                         else
                         {
-                            texCoord0 = texCoords0[i].ReverseUV();
+                            texCoord0 = texCoords0.Value[i].ReverseUV();
                         }
                     }
 
-                    var texCoord1 = texCoords1 != null ? texCoords1[i].ReverseUV() : Vector2.zero;
-                    var color = colors != null ? colors[i] : Color.white;
+                    var texCoord1 = texCoords1 != null ? texCoords1.Value[i].ReverseUV() : Vector2.zero;
+                    var color = colors != null ? colors.Value[i] : Color.white;
                     var joints = jointsGetter?.Invoke(i) ?? (0, 0, 0, 0);
                     var weights = weightsGetter != null ? NormalizeBoneWeight(weightsGetter(i)) : (0, 0, 0, 0);
 
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/PrimitiveExtensions.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/PrimitiveExtensions.cs
index 7e0f9fd08..13e8a3a70 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/PrimitiveExtensions.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MeshIO/PrimitiveExtensions.cs
@@ -1,4 +1,5 @@
 using System;
+using Unity.Collections;
 using UnityEngine;
 
 namespace UniGLTF
@@ -11,12 +12,12 @@ namespace UniGLTF
         public static bool HasSkin(this glTFPrimitives primitives) => primitives.attributes.JOINTS_0 != -1 && primitives.attributes.WEIGHTS_0 != -1;
         public static bool HasColor(this glTFPrimitives primitives) => primitives.attributes.COLOR_0 != -1;
 
-        public static Vector3[] GetPositions(this glTFPrimitives primitives, GltfData data)
+        public static NativeArray<Vector3> GetPositions(this glTFPrimitives primitives, GltfData data)
         {
             return data.GetArrayFromAccessor<Vector3>(primitives.attributes.POSITION);
         }
 
-        public static Vector3[] GetNormals(this glTFPrimitives primitives, GltfData data, int positionsLength)
+        public static NativeArray<Vector3>? GetNormals(this glTFPrimitives primitives, GltfData data, int positionsLength)
         {
             if (!HasNormal(primitives)) return null;
             var result = data.GetArrayFromAccessor<Vector3>(primitives.attributes.NORMAL);
@@ -28,7 +29,7 @@ namespace UniGLTF
             return result;
         }
 
-        public static Vector2[] GetTexCoords0(this glTFPrimitives primitives, GltfData data, int positionsLength)
+        public static NativeArray<Vector2>? GetTexCoords0(this glTFPrimitives primitives, GltfData data, int positionsLength)
         {
             if (!HasTexCoord0(primitives)) return null;
             var result = data.GetArrayFromAccessor<Vector2>(primitives.attributes.TEXCOORD_0);
@@ -39,8 +40,8 @@ namespace UniGLTF
 
             return result;
         }
-        
-        public static Vector2[] GetTexCoords1(this glTFPrimitives primitives, GltfData data, int positionsLength)
+
+        public static NativeArray<Vector2>? GetTexCoords1(this glTFPrimitives primitives, GltfData data, int positionsLength)
         {
             if (!HasTexCoord1(primitives)) return null;
             var result = data.GetArrayFromAccessor<Vector2>(primitives.attributes.TEXCOORD_1);
@@ -48,33 +49,33 @@ namespace UniGLTF
             {
                 throw new Exception("different length");
             }
-            
+
             return result;
         }
 
-        public static Color[] GetColors(this glTFPrimitives primitives, GltfData data, int positionsLength)
+        public static NativeArray<Color>? GetColors(this glTFPrimitives primitives, GltfData data, int positionsLength)
         {
             if (!HasColor(primitives)) return null;
-            
+
             switch (data.GLTF.accessors[primitives.attributes.COLOR_0].TypeCount)
             {
                 case 3:
-                {
-                    var vec3Color = data.GetArrayFromAccessor<Vector3>(primitives.attributes.COLOR_0);
-                    if (vec3Color.Length != positionsLength)
                     {
-                        throw new Exception("different length");
-                    }
-                    var colors = new Color[vec3Color.Length];
+                        var vec3Color = data.GetArrayFromAccessor<Vector3>(primitives.attributes.COLOR_0);
+                        if (vec3Color.Length != positionsLength)
+                        {
+                            throw new Exception("different length");
+                        }
+                        var colors = data.CreateNativeArray<Color>(vec3Color.Length);
 
-                    for (var index = 0; index < vec3Color.Length; index++)
-                    {
-                        var color = vec3Color[index];
-                        colors[index] = new Color(color.x, color.y, color.z);
-                    }
+                        for (var index = 0; index < vec3Color.Length; index++)
+                        {
+                            var color = vec3Color[index];
+                            colors[index] = new Color(color.x, color.y, color.z);
+                        }
 
-                    return colors;
-                }
+                        return colors;
+                    }
                 case 4:
                     var result = data.GetArrayFromAccessor<Color>(primitives.attributes.COLOR_0);
                     if (result.Length != positionsLength)
@@ -89,7 +90,7 @@ namespace UniGLTF
             }
         }
 
-        public static JointsAccessor.Getter GetJoints(this glTFPrimitives primitives,  GltfData data, int positionsLength)
+        public static JointsAccessor.Getter GetJoints(this glTFPrimitives primitives, GltfData data, int positionsLength)
         {
             // skin
             if (!HasSkin(primitives)) return null;
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureImporter.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureImporter.cs
index c14c779b3..bde1d5d2b 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureImporter.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureImporter.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Threading.Tasks;
+using Unity.Collections;
 using UnityEngine;
 using VRMShaders;
 
@@ -201,22 +202,23 @@ namespace UniGLTF
             return data.GLTF.textures[textureIndex].source;
         }
 
-        private static byte[] ToArray(ArraySegment<byte> bytes)
+        private static byte[] ToArray(NativeArray<byte> bytes)
         {
-            if (bytes.Array == null)
-            {
-                return new byte[] { };
-            }
-            else if (bytes.Offset == 0 && bytes.Count == bytes.Array.Length)
-            {
-                return bytes.Array;
-            }
-            else
-            {
-                var result = new byte[bytes.Count];
-                Buffer.BlockCopy(bytes.Array, bytes.Offset, result, 0, result.Length);
-                return result;
-            }
+            // if (bytes.Array == null)
+            // {
+            //     return new byte[] { };
+            // }
+            // else if (bytes.Offset == 0 && bytes.Count == bytes.Array.Length)
+            // {
+            //     return bytes.Array;
+            // }
+            // else
+            // {
+            //     var result = new byte[bytes.Count];
+            //     Buffer.BlockCopy(bytes.Array, bytes.Offset, result, 0, result.Length);
+            //     return result;
+            // }
+            return bytes.ToArray();
         }
     }
 }
diff --git a/Assets/VRM10/Runtime/IO/Vrm10Data.cs b/Assets/VRM10/Runtime/IO/Vrm10Data.cs
index 6e38ca237..27353acc7 100644
--- a/Assets/VRM10/Runtime/IO/Vrm10Data.cs
+++ b/Assets/VRM10/Runtime/IO/Vrm10Data.cs
@@ -14,7 +14,7 @@ namespace UniVRM10
         Other,
     }
 
-    public class Vrm10Data
+    public class Vrm10Data : IDisposable
     {
         public GltfData Data { get; }
         public UniGLTF.Extensions.VRMC_vrm.VRMC_vrm VrmExtension { get; }
@@ -86,77 +86,85 @@ namespace UniVRM10
             // try migrateion
             byte[] migrated = default;
             Migration.Vrm0Meta oldMeta = default;
-            try
+            using (data)
             {
-                var json = data.Json.ParseAsJson();
                 try
                 {
-                    if (!json.TryGet("extensions", out JsonNode extensions))
+                    var json = data.Json.ParseAsJson();
+                    try
                     {
-                        result = new Vrm10Data(default, default, Vrm10FileType.Other, "gltf: no extensions");
+                        if (!json.TryGet("extensions", out JsonNode extensions))
+                        {
+                            result = new Vrm10Data(default, default, Vrm10FileType.Other, "gltf: no extensions");
+                            return false;
+                        }
+                        if (!extensions.TryGet("VRM", out JsonNode vrm0))
+                        {
+                            result = new Vrm10Data(default, default, Vrm10FileType.Other, "gltf: no vrm0");
+                            return false;
+                        }
+                    }
+                    catch (Exception ex)
+                    {
+                        result = new Vrm10Data(default, default, Vrm10FileType.Other, $"error: {ex}");
                         return false;
                     }
-                    if (!extensions.TryGet("VRM", out JsonNode vrm0))
+
+                    if (!doMigrate)
                     {
-                        result = new Vrm10Data(default, default, Vrm10FileType.Other, "gltf: no vrm0");
+                        result = new Vrm10Data(default, default, Vrm10FileType.Vrm0, "vrm0: not migrated");
                         return false;
                     }
+
+                    migrated = MigrationVrm.Migrate(data);
+                    if (migrated == null)
+                    {
+                        result = new Vrm10Data(default, default, Vrm10FileType.Vrm0, "vrm0: cannot migrate");
+                        return false;
+                    }
+
+                    oldMeta = Migration.Vrm0Meta.FromJsonBytes(json);
                 }
                 catch (Exception ex)
                 {
-                    result = new Vrm10Data(default, default, Vrm10FileType.Other, $"error: {ex}");
+                    result = new Vrm10Data(default, default, Vrm10FileType.Vrm0, $"vrm0: migration error: {ex}");
                     return false;
                 }
 
-                if (!doMigrate)
                 {
-                    result = new Vrm10Data(default, default, Vrm10FileType.Vrm0, "vrm0: not migrated");
-                    return false;
-                }
-
-                migrated = MigrationVrm.Migrate(data);
-                if (migrated == null)
-                {
-                    result = new Vrm10Data(default, default, Vrm10FileType.Vrm0, "vrm0: cannot migrate");
-                    return false;
-                }
-
-                oldMeta = Migration.Vrm0Meta.FromJsonBytes(json);
-            }
-            catch (Exception ex)
-            {
-                result = new Vrm10Data(default, default, Vrm10FileType.Vrm0, $"vrm0: migration error: {ex}");
-                return false;
-            }
-
-            {
-                var migratedData = new GlbLowLevelParser(data.TargetPath, migrated).Parse();
-                if (UniGLTF.Extensions.VRMC_vrm.GltfDeserializer.TryGet(migratedData.GLTF.extensions, out VRMC_vrm vrm))
-                {
-                    // success
-                    if (oldMeta == null)
+                    var migratedData = new GlbLowLevelParser(data.TargetPath, migrated).Parse();
+                    if (UniGLTF.Extensions.VRMC_vrm.GltfDeserializer.TryGet(migratedData.GLTF.extensions, out VRMC_vrm vrm))
                     {
-                        throw new NullReferenceException("oldMeta");
-                    }
-                    byte[] migratedBytes = null;
-                    if (VRMShaders.Symbols.VRM_DEVELOP)
-                    {
-                        // 右手左手座標変換でバッファが破壊的変更されるので、コピーを作っている        
-                        migratedBytes = migrated.Select(x => x).ToArray();
+                        // success
+                        if (oldMeta == null)
+                        {
+                            throw new NullReferenceException("oldMeta");
+                        }
+                        byte[] migratedBytes = null;
+                        if (VRMShaders.Symbols.VRM_DEVELOP)
+                        {
+                            // 右手左手座標変換でバッファが破壊的変更されるので、コピーを作っている        
+                            migratedBytes = migrated.Select(x => x).ToArray();
+                        }
+
+                        result = new Vrm10Data(migratedData, vrm, Vrm10FileType.Vrm0,
+                            message: "vrm0: migrated",
+                            oldMeta: oldMeta,
+                            migratedBytes: migratedBytes
+                            );
+
+                        return true;
                     }
 
-                    result = new Vrm10Data(migratedData, vrm, Vrm10FileType.Vrm0,
-                        message: "vrm0: migrated",
-                        oldMeta: oldMeta,
-                        migratedBytes: migratedBytes
-                        );
-
-                    return true;
+                    result = new Vrm10Data(default, default, Vrm10FileType.Vrm0, "vrm0: migrate but error ?");
+                    return false;
                 }
-
-                result = new Vrm10Data(default, default, Vrm10FileType.Vrm0, "vrm0: migrate but error ?");
-                return false;
             }
         }
+
+        public void Dispose()
+        {
+            Data.Dispose();
+        }
     }
 }
diff --git a/Assets/VRM10/Runtime/IO/Vrm10Storage.cs b/Assets/VRM10/Runtime/IO/Vrm10Storage.cs
index c79730938..4fd8adadd 100644
--- a/Assets/VRM10/Runtime/IO/Vrm10Storage.cs
+++ b/Assets/VRM10/Runtime/IO/Vrm10Storage.cs
@@ -55,7 +55,7 @@ namespace UniVRM10
                 gltfVrmSpringBone = springBone;
             }
 
-            _buffer = new ArraySegmentByteBuffer(data.Bin);
+            _buffer = new ArraySegmentByteBuffer(new ArraySegment<byte>(data.Bin.ToArray()));
         }
 
         public void Reserve(int bytesLength)
diff --git a/Assets/VRM10/Runtime/Migration/MeshUpdater.cs b/Assets/VRM10/Runtime/Migration/MeshUpdater.cs
index 9538a818c..f20040456 100644
--- a/Assets/VRM10/Runtime/Migration/MeshUpdater.cs
+++ b/Assets/VRM10/Runtime/Migration/MeshUpdater.cs
@@ -20,7 +20,7 @@ namespace UniVRM10
         public MeshUpdater(GltfData data)
         {
             _data = data;
-            _buffer = new ArrayByteBuffer(new byte[data.Bin.Count]);
+            _buffer = new ArrayByteBuffer(new byte[data.Bin.Length]);
         }
 
         int AddBuffer(ArraySegment<byte> bytes)
@@ -70,7 +70,7 @@ namespace UniVRM10
             foreach (var image in gltf.images)
             {
                 var bytes = _data.GetBytesFromBufferView(image.bufferView);
-                image.bufferView = AddBuffer(bytes);
+                image.bufferView = AddBuffer(new ArraySegment<byte>(bytes.ToArray()));
             }
 
             // update Mesh
diff --git a/Assets/VRM10/Runtime/Migration/RotateY180.cs b/Assets/VRM10/Runtime/Migration/RotateY180.cs
index 4ada62c1c..93bb4203c 100644
--- a/Assets/VRM10/Runtime/Migration/RotateY180.cs
+++ b/Assets/VRM10/Runtime/Migration/RotateY180.cs
@@ -73,7 +73,7 @@ namespace UniVRM10
             if (bufferViewIndex != -1)
             {
                 var buffer = data.GetBytesFromBufferView(bufferViewIndex);
-                var span = SpanLike.Wrap<UnityEngine.Vector3>(buffer);
+                var span = buffer.Reinterpret<UnityEngine.Vector3>(1);
                 for (int i = 0; i < span.Length; ++i)
                 {
                     span[i] = span[i].RotateY180();
@@ -114,7 +114,7 @@ namespace UniVRM10
                 {
                     var accessor = data.GLTF.accessors[skin.inverseBindMatrices];
                     var buffer = data.GetBytesFromBufferView(accessor.bufferView);
-                    var span = SpanLike.Wrap<UnityEngine.Matrix4x4>(buffer);
+                    var span = buffer.Reinterpret<UnityEngine.Matrix4x4>(1);
                     for (int i = 0; i < span.Length; ++i)
                     {
                         span[i] = span[i].RotateY180();