diff --git a/Assets/UniGLTF/Runtime/UniGLTF/Resources/Shaders/NormalMapEncoder.shader b/Assets/UniGLTF/Runtime/UniGLTF/Resources/Shaders/NormalMapEncoder.shader
deleted file mode 100644
index 8c77bb20b..000000000
--- a/Assets/UniGLTF/Runtime/UniGLTF/Resources/Shaders/NormalMapEncoder.shader
+++ /dev/null
@@ -1,68 +0,0 @@
-Shader "UniGLTF/NormalMapEncoder"
-{
-	Properties
-	{
-		_MainTex("Texture", 2D) = "white" {}
-	}
-	SubShader
-	{
-		// No culling or depth
-		Cull Off ZWrite Off ZTest Always
-
-		Pass
-		{
-			CGPROGRAM
-			#pragma vertex vert
-			#pragma fragment frag
-
-			#include "UnityCG.cginc"
-
-			struct appdata
-			{
-				float4 vertex : POSITION;
-				float2 uv : TEXCOORD0;
-			};
-
-			struct v2f
-			{
-				float2 uv : TEXCOORD0;
-				float4 vertex : SV_POSITION;
-			};
-
-			v2f vert(appdata v)
-			{
-				v2f o;
-				o.vertex = UnityObjectToClipPos(v.vertex);
-				o.uv = v.uv;
-				return o;
-			}
-
-			sampler2D _MainTex;
-
-			fixed4 frag(v2f i) : SV_Target
-			{
-				half4 col = tex2D(_MainTex, i.uv);
-
-				half4 packedNormal;
-				packedNormal.x = col.x;
-				packedNormal.y = col.y;
-				packedNormal.z = col.z;
-				packedNormal.w = 1.0;
-
-				// normalize as normal vector
-				float3 normal;
-				normal.xy = packedNormal.xy * 2 - 1;
-				if (dot(normal.xy, normal.xy) > 1)
-				{
-					normal.xy = normalize(normal.xy);
-				}
-				normal.z = sqrt(1 - saturate(dot(normal.xy, normal.xy)));
-
-				packedNormal.xyz = normal.xyz * 0.5 + 0.5;
-				return packedNormal;
-			}
-			ENDCG
-		}
-	}
-}
-
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/Resources/Shaders/NormalMapEncoder.shader.meta b/Assets/UniGLTF/Runtime/UniGLTF/Resources/Shaders/NormalMapEncoder.shader.meta
deleted file mode 100644
index d0ef10022..000000000
--- a/Assets/UniGLTF/Runtime/UniGLTF/Resources/Shaders/NormalMapEncoder.shader.meta
+++ /dev/null
@@ -1,9 +0,0 @@
-fileFormatVersion: 2
-guid: 3e39586253f31b34f87fa7e133449b1e
-ShaderImporter:
-  externalObjects: {}
-  defaultTextures: []
-  nonModifiableTextures: []
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 
diff --git a/Assets/VRMShaders/GLTF/IO/Runtime/NormalConverter.cs b/Assets/VRMShaders/GLTF/IO/Runtime/NormalConverter.cs
index 88180aa2a..bd9ea9bf6 100644
--- a/Assets/VRMShaders/GLTF/IO/Runtime/NormalConverter.cs
+++ b/Assets/VRMShaders/GLTF/IO/Runtime/NormalConverter.cs
@@ -17,28 +17,13 @@ namespace VRMShaders
             }
         }
 
-        private static Material m_encoder;
-        private static Material Encoder
-        {
-            get
-            {
-                if (m_encoder == null)
-                {
-                    m_encoder = new Material(Shader.Find("UniGLTF/NormalMapEncoder"));
-                }
-                return m_encoder;
-            }
-        }
-
         // GLTF data to Unity texture
-        // ConvertToNormalValueFromRawColorWhenCompressionIsRequired
         public static Texture2D Import(Texture2D texture)
         {
-            return TextureConverter.CopyTexture(texture, ColorSpace.Linear, false, Encoder);
+            return texture;
         }
 
         // Unity texture to GLTF data
-        // ConvertToRawColorWhenNormalValueIsCompressed
         public static Texture2D Export(Texture texture)
         {
             return TextureConverter.CopyTexture(texture, ColorSpace.Linear, false, Decoder);
diff --git a/Assets/VRMShaders/GLTF/IO/Runtime/TextureFactory.cs b/Assets/VRMShaders/GLTF/IO/Runtime/TextureFactory.cs
index bf2f34425..d3bc48f0c 100644
--- a/Assets/VRMShaders/GLTF/IO/Runtime/TextureFactory.cs
+++ b/Assets/VRMShaders/GLTF/IO/Runtime/TextureFactory.cs
@@ -61,13 +61,9 @@ namespace VRMShaders
         }
 
         /// <summary>
-        /// テクスチャーをロード、必要であれば変換して返す。
-        /// 同じものはキャッシュを返す
+        /// テクスチャ生成情報を基に、テクスチャ生成を行う。
+        /// SubAssetKey が同じ場合はキャッシュを返す。
         /// </summary>
-        /// <param name="texture_type">変換の有無を判断する: METALLIC_GLOSS_PROP</param>
-        /// <param name="roughnessFactor">METALLIC_GLOSS_PROPの追加パラメーター</param>
-        /// <param name="indices">gltf の texture index</param>
-        /// <returns></returns>
         public async Task<Texture> GetTextureAsync(TextureDescriptor texDesc)
         {
             var subAssetKey = texDesc.SubAssetKey;
@@ -86,15 +82,16 @@ namespace VRMShaders
             {
                 case TextureImportTypes.NormalMap:
                 {
-                    // Runtime/SubAsset 用に変換する
+                    // no conversion. Unity's normal map is same with glTF's.
+                    //
+                    // > contrary to Unity’s usual convention of using Y as “up”
+                    // https://docs.unity3d.com/2018.4/Documentation/Manual/StandardShaderMaterialParameterNormalMap.html
                     var data0 = await texDesc.Index0();
                     var rawTexture = await _textureDeserializer.LoadTextureAsync(data0, texDesc.Sampler.EnableMipMap, ColorSpace.Linear);
-                    var convertedTexture = NormalConverter.Import(rawTexture);
-                    convertedTexture.name = subAssetKey.Name;
-                    convertedTexture.SetSampler(texDesc.Sampler);
-                    _textureCache.Add(subAssetKey, convertedTexture);
-                    DestroyResource(rawTexture);
-                    return convertedTexture;
+                    rawTexture.name = subAssetKey.Name;
+                    rawTexture.SetSampler(texDesc.Sampler);
+                    _textureCache.Add(subAssetKey, rawTexture);
+                    return rawTexture;
                 }
 
                 case TextureImportTypes.StandardMap: