diff --git a/Assets/VRM10_Samples/ClothSample/RotateParticle/Runtime/Jobs/RotateParticleJobSystem.cs b/Assets/VRM10_Samples/ClothSample/RotateParticle/Runtime/Jobs/RotateParticleJobSystem.cs
index 5fe5fc812..05fac9621 100644
--- a/Assets/VRM10_Samples/ClothSample/RotateParticle/Runtime/Jobs/RotateParticleJobSystem.cs
+++ b/Assets/VRM10_Samples/ClothSample/RotateParticle/Runtime/Jobs/RotateParticleJobSystem.cs
@@ -37,8 +37,8 @@ namespace RotateParticle.Jobs
         //
         // cloth
         //
-        NativeArray<int> _clothUsedParticles = new();
-        NativeArray<(SpringConstraint, SphereTriangle.ClothRect)> _clothRects = new();
+        NativeArray<bool> _clothUsedParticles;
+        NativeArray<(SpringConstraint, SphereTriangle.ClothRect)> _clothRects;
 
         void IDisposable.Dispose()
         {
@@ -53,6 +53,9 @@ namespace RotateParticle.Jobs
             if (_prevPositions.IsCreated) _prevPositions.Dispose();
             if (_nextPositions.IsCreated) _nextPositions.Dispose();
             if (_nextRotations.IsCreated) _nextRotations.Dispose();
+
+            if (_clothUsedParticles.IsCreated) _clothUsedParticles.Dispose();
+            if (_clothRects.IsCreated) _clothRects.Dispose();
         }
 
         (int index, bool isNew) GetTransformIndex(Transform t,
@@ -178,8 +181,8 @@ namespace RotateParticle.Jobs
             //
             // cloths
             //
-            HashSet<int> clothUsedParticles = new();
             List<(SpringConstraint, SphereTriangle.ClothRect)> clothRects = new();
+            _clothUsedParticles = new(_transforms.Count, Allocator.Persistent);
             var cloths = vrm.GetComponentsInChildren<RectCloth>();
             foreach (var cloth in cloths)
             {
@@ -196,10 +199,10 @@ namespace RotateParticle.Jobs
                         var b = s1.Particles[j];
                         var c = s1.Particles[j - 1];
                         var d = s0.Particles[j - 1];
-                        clothUsedParticles.Add(_transforms.IndexOf(a.Transform));
-                        clothUsedParticles.Add(_transforms.IndexOf(b.Transform));
-                        clothUsedParticles.Add(_transforms.IndexOf(c.Transform));
-                        clothUsedParticles.Add(_transforms.IndexOf(d.Transform));
+                        _clothUsedParticles[_transforms.IndexOf(a.Transform)] = true;
+                        _clothUsedParticles[_transforms.IndexOf(b.Transform)] = true;
+                        _clothUsedParticles[_transforms.IndexOf(c.Transform)] = true;
+                        _clothUsedParticles[_transforms.IndexOf(d.Transform)] = true;
                         if (i % 2 == 1)
                         {
                             // 互い違いに
@@ -234,10 +237,10 @@ namespace RotateParticle.Jobs
                         var b = s1.Particles[j];
                         var c = s1.Particles[j - 1];
                         var d = s0.Particles[j - 1];
-                        clothUsedParticles.Add(_transforms.IndexOf(a.Transform));
-                        clothUsedParticles.Add(_transforms.IndexOf(b.Transform));
-                        clothUsedParticles.Add(_transforms.IndexOf(c.Transform));
-                        clothUsedParticles.Add(_transforms.IndexOf(d.Transform));
+                        _clothUsedParticles[_transforms.IndexOf(a.Transform)] = true;
+                        _clothUsedParticles[_transforms.IndexOf(b.Transform)] = true;
+                        _clothUsedParticles[_transforms.IndexOf(c.Transform)] = true;
+                        _clothUsedParticles[_transforms.IndexOf(d.Transform)] = true;
                         if (i % 2 == 1)
                         {
                             // 互い違いに
@@ -263,6 +266,7 @@ namespace RotateParticle.Jobs
                     }
                 }
             }
+            _clothRects = new(clothRects.ToArray(), Allocator.Persistent);
         }
 
         private static BlittableColliderType TranslateColliderType(VRM10SpringBoneColliderTypes colliderType)
diff --git a/Assets/VRM10_Samples/ClothSample/RotateParticle/Runtime/RotateParticleSystem.cs b/Assets/VRM10_Samples/ClothSample/RotateParticle/Runtime/RotateParticleSystem.cs
index 50f3296ff..2ad1aa1f3 100644
--- a/Assets/VRM10_Samples/ClothSample/RotateParticle/Runtime/RotateParticleSystem.cs
+++ b/Assets/VRM10_Samples/ClothSample/RotateParticle/Runtime/RotateParticleSystem.cs
@@ -56,7 +56,7 @@ namespace RotateParticle
             return Color.gray;
         }
 
-        HashSet<int> _clothUsedParticles = new();
+        bool[] _clothUsedParticles;
 
         void IDisposable.Dispose()
         {
@@ -67,6 +67,7 @@ namespace RotateParticle
             ParticleList list,
             Dictionary<WarpRoot, Strand> strandMap)
         {
+            _clothUsedParticles = new bool[_list._particles.Count];
             for (int i = 1; i < cloth.Warps.Count; ++i)
             {
                 var s0 = strandMap[cloth.Warps[i - 1]];
@@ -80,10 +81,10 @@ namespace RotateParticle
                     var b = s1.Particles[j];
                     var c = s1.Particles[j - 1];
                     var d = s0.Particles[j - 1];
-                    _clothUsedParticles.Add(a.Init.Index);
-                    _clothUsedParticles.Add(b.Init.Index);
-                    _clothUsedParticles.Add(c.Init.Index);
-                    _clothUsedParticles.Add(d.Init.Index);
+                    _clothUsedParticles[a.Init.Index] = true;
+                    _clothUsedParticles[b.Init.Index] = true;
+                    _clothUsedParticles[c.Init.Index] = true;
+                    _clothUsedParticles[d.Init.Index] = true;
                     if (i % 2 == 1)
                     {
                         // 互い違いに
@@ -116,10 +117,10 @@ namespace RotateParticle
                     var b = s1.Particles[j];
                     var c = s1.Particles[j - 1];
                     var d = s0.Particles[j - 1];
-                    _clothUsedParticles.Add(a.Init.Index);
-                    _clothUsedParticles.Add(b.Init.Index);
-                    _clothUsedParticles.Add(c.Init.Index);
-                    _clothUsedParticles.Add(d.Init.Index);
+                    _clothUsedParticles[a.Init.Index] = true;
+                    _clothUsedParticles[b.Init.Index] = true;
+                    _clothUsedParticles[c.Init.Index] = true;
+                    _clothUsedParticles[d.Init.Index] = true;
                     if (i % 2 == 1)
                     {
                         // 互い違いに
@@ -268,7 +269,7 @@ namespace RotateParticle
                     for (int j = 0; j < _list._particles.Count; ++j)
                     {
                         // using var prof = new ProfileSample("Collision: Strand");
-                        if (_clothUsedParticles.Contains(j))
+                        if (_clothUsedParticles[j])
                         {
                             // 布で処理された
                             continue;