diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs
index ce31fbc6c..60f0ad957 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContext.cs
@@ -48,7 +48,7 @@ namespace UniGLTF
             MaterialDescriptorGenerator = materialGenerator ?? MaterialDescriptorGeneratorUtility.GetValidGltfMaterialDescriptorGenerator();
 
             ExternalObjectMap = externalObjectMap ?? new Dictionary<SubAssetKey, UnityEngine.Object>();
-            textureDeserializer = textureDeserializer ?? new UnityTextureDeserializer();
+            textureDeserializer = textureDeserializer ?? new UnityTextureDeserializer(_settings.MarkNonReadable);
 
             TextureFactory = new TextureFactory(textureDeserializer, ExternalObjectMap
                 .Where(x => x.Value is Texture)
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContextSettings.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContextSettings.cs
index 262a71719..f4eda4b50 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContextSettings.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/ImporterContextSettings.cs
@@ -1,19 +1,47 @@
-namespace UniGLTF
+using UnityEngine;
+
+namespace UniGLTF
 {
+    /// <summary>
+    /// ImporterContext層の設定はここに。
+    /// さすれば、VRMとVRM10を変えずに設定を追加できる。
+    /// </summary>
     public class ImporterContextSettings
     {
         public bool LoadAnimation { get; }
         public Axes InvertAxis { get; }
+        public bool TextureIsReadalbe { get; }
+        public bool MarkNonReadable => !TextureIsReadalbe;
 
         /// <summary>
         /// ImporterContextの設定を指定する。
         /// </summary>
         /// <param name="loadAnimation">アニメーションをインポートする場合はtrueを指定(初期値はtrue)</param>
         /// <param name="invertAxis">GLTF から Unity に変換するときに反転させる軸を指定(初期値はAxes.Z)</param>
-        public ImporterContextSettings(bool loadAnimation = true, Axes invertAxis = Axes.Z)
+        /// <param name="textureIsReadable">textureのbitmapにアクセスするか(初期値はEditorの場合はtrue。それ以外はfalse)</param>
+        public ImporterContextSettings(
+            bool loadAnimation = true,
+            Axes invertAxis = Axes.Z,
+            bool? textureIsReadable = default)
         {
             LoadAnimation = loadAnimation;
             InvertAxis = invertAxis;
+            if (textureIsReadable.HasValue)
+            {
+                TextureIsReadalbe = textureIsReadable.Value;
+            }
+            else
+            {
+                if (Application.isEditor)
+                {
+                    TextureIsReadalbe = true;
+                }
+                else
+                {
+                    // v0.128.4 からの挙動変更
+                    TextureIsReadalbe = false;
+                }
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/Import/UnitySupportedImageTypeDeserializer.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/Import/UnitySupportedImageTypeDeserializer.cs
index 05a71c1df..1ae7b6f89 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/Import/UnitySupportedImageTypeDeserializer.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/Import/UnitySupportedImageTypeDeserializer.cs
@@ -14,12 +14,19 @@ namespace UniGLTF
         /// </summary>
         /// <remarks>
         /// `UnityEngine.ImageConversion.LoadImage` の第二引数 `markNonReadable` に相当。
-        /// デフォルト値は `false`。
         /// テクスチャ編集を行わないアプリケーションプログラム等では、
         /// この値を `true` にすることでメモリ使用量の削減を期待できる。
         /// このフラグの効用については `UnityEngine.Texture2D.Apply` に記述がある。
+        /// 
+        /// v0.128.4
+        /// default は ImporterContextSettings.MarkNonReadable に従う
         /// </remarks>
-        public bool MarkNonReadable { get; set; } = false;
+        public bool MarkNonReadable { get; }
+
+        public UnitySupportedImageTypeDeserializer(bool markNonReadable)
+        {
+            MarkNonReadable = markNonReadable;
+        }
 
         public async Task<Texture2D> LoadTextureAsync(DeserializingTextureInfo textureInfo, IAwaitCaller awaitCaller)
         {
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/Import/UnityTextureDeserializer.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/Import/UnityTextureDeserializer.cs
index 491f89757..7ce56bbad 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/Import/UnityTextureDeserializer.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/Import/UnityTextureDeserializer.cs
@@ -8,9 +8,14 @@ namespace UniGLTF
     /// </summary>
     public sealed class UnityTextureDeserializer : ITextureDeserializer
     {
-        private readonly UnitySupportedImageTypeDeserializer _unitySupportedDeserializer = new();
+        private readonly UnitySupportedImageTypeDeserializer _unitySupportedDeserializer;
         private readonly KtxTextureDeserializer _ktxTextureDeserializer = new();
 
+        public UnityTextureDeserializer(bool markNonReadable)
+        {
+            _unitySupportedDeserializer = new(markNonReadable);
+        }
+
         public async Task<Texture2D> LoadTextureAsync(DeserializingTextureInfo textureInfo, IAwaitCaller awaitCaller)
         {
             Texture2D texture = null;