diff --git a/Assets/UnityScreenNavigator/Runtime/Core/Modal/Modal.cs b/Assets/UnityScreenNavigator/Runtime/Core/Modal/Modal.cs
index 04d15ac..f98fd48 100644
--- a/Assets/UnityScreenNavigator/Runtime/Core/Modal/Modal.cs
+++ b/Assets/UnityScreenNavigator/Runtime/Core/Modal/Modal.cs
@@ -323,6 +323,12 @@ internal void AfterExit(bool push, Modal partnerModal)
             IsTransitioning = false;
             TransitionAnimationType = null;
         }
+        
+        internal void BeforeReleaseAndForget()
+        {
+            foreach (var lifecycleEvent in _lifecycleEvents)
+                lifecycleEvent.Cleanup();
+        }
 
         internal AsyncProcessHandle BeforeRelease()
         {
diff --git a/Assets/UnityScreenNavigator/Runtime/Core/Modal/ModalContainer.cs b/Assets/UnityScreenNavigator/Runtime/Core/Modal/ModalContainer.cs
index f06a7e6..43f16dc 100644
--- a/Assets/UnityScreenNavigator/Runtime/Core/Modal/ModalContainer.cs
+++ b/Assets/UnityScreenNavigator/Runtime/Core/Modal/ModalContainer.cs
@@ -30,7 +30,7 @@ public sealed class ModalContainer : MonoBehaviour
         private readonly Dictionary<string, AssetLoadHandle<GameObject>> _assetLoadHandles
             = new Dictionary<string, AssetLoadHandle<GameObject>>();
 
-        private readonly List<ModalBackdrop> _backdrops = new List<ModalBackdrop>();
+        public List<ModalBackdrop> Backdrops { get; } = new List<ModalBackdrop>();
 
         private readonly List<IModalContainerCallbackReceiver> _callbackReceivers =
             new List<IModalContainerCallbackReceiver>();
@@ -100,6 +100,8 @@ private void OnDestroy()
                 var modal = _modals[modalId];
                 var assetLoadHandle = _assetLoadHandles[modalId];
 
+                if (UnityScreenNavigatorSettings.Instance.CallCleanupWhenDestroy)
+                    modal.BeforeReleaseAndForget();
                 Destroy(modal.gameObject);
                 AssetLoader.Release(assetLoadHandle);
             }
@@ -304,7 +306,7 @@ private IEnumerator PushRoutine(Type modalType, string resourceKey, bool playAni
 
             var backdrop = Instantiate(_backdropPrefab);
             backdrop.Setup((RectTransform)transform);
-            _backdrops.Add(backdrop);
+            Backdrops.Add(backdrop);
 
             var instance = Instantiate(assetLoadHandle.Result);
             if (!instance.TryGetComponent(modalType, out var c))
@@ -425,7 +427,7 @@ private IEnumerator PopRoutine(bool playAnimation, int popCount = 1)
                 var unusedModalId = _orderedModalIds[i];
                 unusedModalIds.Add(unusedModalId);
                 unusedModals.Add(_modals[unusedModalId]);
-                unusedBackdrops.Add(_backdrops[i]);
+                unusedBackdrops.Add(Backdrops[i]);
             }
 
             var enterModalIndex = _orderedModalIds.Count - popCount - 1;
@@ -495,7 +497,7 @@ private IEnumerator PopRoutine(bool playAnimation, int popCount = 1)
 
             foreach (var unusedBackdrop in unusedBackdrops)
             {
-                _backdrops.Remove(unusedBackdrop);
+                Backdrops.Remove(unusedBackdrop);
                 Destroy(unusedBackdrop.gameObject);
             }
 
diff --git a/Assets/UnityScreenNavigator/Runtime/Core/Page/Page.cs b/Assets/UnityScreenNavigator/Runtime/Core/Page/Page.cs
index 773f6f4..e48e473 100644
--- a/Assets/UnityScreenNavigator/Runtime/Core/Page/Page.cs
+++ b/Assets/UnityScreenNavigator/Runtime/Core/Page/Page.cs
@@ -330,6 +330,12 @@ internal void AfterExit(bool push, Page partnerPage)
             IsTransitioning = false;
             TransitionAnimationType = null;
         }
+        
+        internal void BeforeReleaseAndForget()
+        {
+            foreach (var lifecycleEvent in _lifecycleEvents)
+                lifecycleEvent.Cleanup();
+        }
 
         internal AsyncProcessHandle BeforeRelease()
         {
diff --git a/Assets/UnityScreenNavigator/Runtime/Core/Page/PageContainer.cs b/Assets/UnityScreenNavigator/Runtime/Core/Page/PageContainer.cs
index 9403735..cd37a84 100644
--- a/Assets/UnityScreenNavigator/Runtime/Core/Page/PageContainer.cs
+++ b/Assets/UnityScreenNavigator/Runtime/Core/Page/PageContainer.cs
@@ -93,6 +93,8 @@ private void OnDestroy()
                 var page = _pages[pageId];
                 var assetLoadHandle = _assetLoadHandles[pageId];
 
+                if (UnityScreenNavigatorSettings.Instance.CallCleanupWhenDestroy)
+                    page.BeforeReleaseAndForget();
                 Destroy(page.gameObject);
                 AssetLoader.Release(assetLoadHandle);
             }
diff --git a/Assets/UnityScreenNavigator/Runtime/Core/Shared/UnityScreenNavigatorSettings.cs b/Assets/UnityScreenNavigator/Runtime/Core/Shared/UnityScreenNavigatorSettings.cs
index 7ab5cd5..3f6b6f0 100644
--- a/Assets/UnityScreenNavigator/Runtime/Core/Shared/UnityScreenNavigatorSettings.cs
+++ b/Assets/UnityScreenNavigator/Runtime/Core/Shared/UnityScreenNavigatorSettings.cs
@@ -45,6 +45,8 @@ internal sealed class UnityScreenNavigatorSettings : ScriptableObject
 
         [EnabledIf(nameof(_enableInteractionInTransition), false)] [SerializeField]
         private bool _controlInteractionsOfAllContainers = true;
+        
+        [SerializeField] private bool _callCleanupWhenDestroy = true;
 
         private IAssetLoader _defaultAssetLoader;
         private ModalBackdrop _defaultModalBackdrop;
@@ -191,6 +193,12 @@ public ITransitionAnimation GetDefaultSheetTransitionAnimation(bool enter)
         {
             return enter ? SheetEnterAnimation : SheetExitAnimation;
         }
+        
+        public bool CallCleanupWhenDestroy
+        {
+            get => _callCleanupWhenDestroy;
+            set => _callCleanupWhenDestroy = value;
+        }
 
 #if UNITY_EDITOR
 
diff --git a/Assets/UnityScreenNavigator/Runtime/Core/Sheet/Sheet.cs b/Assets/UnityScreenNavigator/Runtime/Core/Sheet/Sheet.cs
index ff530be..56d62a8 100644
--- a/Assets/UnityScreenNavigator/Runtime/Core/Sheet/Sheet.cs
+++ b/Assets/UnityScreenNavigator/Runtime/Core/Sheet/Sheet.cs
@@ -282,10 +282,10 @@ internal void AfterExit(Sheet partnerSheet)
             TransitionAnimationType = null;
         }
 
-        internal AsyncProcessHandle BeforeRelease()
+        internal void BeforeReleaseAndForget()
         {
-            // Evaluate here because users may add/remove lifecycle events within the lifecycle events.
-            return CoroutineManager.Instance.Run(CreateCoroutine(_lifecycleEvents.Select(x => x.Cleanup()).ToArray()));
+            foreach (var lifecycleEvent in _lifecycleEvents)
+                lifecycleEvent.Cleanup();
         }
 
 #if USN_USE_ASYNC_METHODS
diff --git a/Assets/UnityScreenNavigator/Runtime/Core/Sheet/SheetContainer.cs b/Assets/UnityScreenNavigator/Runtime/Core/Sheet/SheetContainer.cs
index f900c02..994e496 100644
--- a/Assets/UnityScreenNavigator/Runtime/Core/Sheet/SheetContainer.cs
+++ b/Assets/UnityScreenNavigator/Runtime/Core/Sheet/SheetContainer.cs
@@ -448,7 +448,11 @@ private IEnumerator HideRoutine(bool playAnimation)
         public void UnregisterAll()
         {
             foreach (var sheet in _sheets.Values)
+            {
+                if (UnityScreenNavigatorSettings.Instance.CallCleanupWhenDestroy)
+                    sheet.BeforeReleaseAndForget();
                 Destroy(sheet.gameObject);
+            }
 
             foreach (var assetLoadHandle in _assetLoadHandles.Values)
                 AssetLoader.Release(assetLoadHandle);
diff --git a/Assets/UnityScreenNavigator/package.json b/Assets/UnityScreenNavigator/package.json
index 5f38263..222c6cc 100644
--- a/Assets/UnityScreenNavigator/package.json
+++ b/Assets/UnityScreenNavigator/package.json
@@ -2,7 +2,7 @@
   "name": "com.harumak.unityscreennavigator",
   "displayName": "UnityScreenNavigator",
   "version": "1.6.5",
-  "unity": "2019.4",
+  "unity": "2021.3",
   "license": "MIT",
   "dependencies": {
   },
diff --git a/Packages/manifest.json b/Packages/manifest.json
index c8a6ac1..cfad260 100644
--- a/Packages/manifest.json
+++ b/Packages/manifest.json
@@ -4,14 +4,14 @@
     "com.harumak.unityuiplayables": "https://github.com/Haruma-K/UnityUIPlayables.git?path=/Assets/UnityUIPlayables",
     "com.neuecc.unirx": "https://github.com/neuecc/UniRx.git?path=Assets/Plugins/UniRx/Scripts",
     "com.unity.2d.sprite": "1.0.0",
-    "com.unity.addressables": "1.17.17",
-    "com.unity.collab-proxy": "1.6.0",
-    "com.unity.ide.rider": "1.2.1",
-    "com.unity.ide.visualstudio": "2.0.9",
-    "com.unity.ide.vscode": "1.2.3",
-    "com.unity.test-framework": "1.1.27",
-    "com.unity.textmeshpro": "2.1.6",
-    "com.unity.timeline": "1.2.18",
+    "com.unity.addressables": "1.19.19",
+    "com.unity.collab-proxy": "2.0.4",
+    "com.unity.ide.rider": "3.0.21",
+    "com.unity.ide.visualstudio": "2.0.18",
+    "com.unity.ide.vscode": "1.2.5",
+    "com.unity.test-framework": "1.1.31",
+    "com.unity.textmeshpro": "3.0.6",
+    "com.unity.timeline": "1.6.5",
     "com.unity.ugui": "1.0.0",
     "com.unity.modules.ai": "1.0.0",
     "com.unity.modules.androidjni": "1.0.0",
diff --git a/Packages/packages-lock.json b/Packages/packages-lock.json
index 7ba2350..37449f2 100644
--- a/Packages/packages-lock.json
+++ b/Packages/packages-lock.json
@@ -5,7 +5,7 @@
       "depth": 0,
       "source": "git",
       "dependencies": {},
-      "hash": "73d86259ce31ce7f4dfe1d028ea1c3edf96c23e4"
+      "hash": "66de0d3a58b256b6e0194f285cc530fd0c08407b"
     },
     "com.harumak.unityuiplayables": {
       "version": "https://github.com/Haruma-K/UnityUIPlayables.git?path=/Assets/UnityUIPlayables",
@@ -15,14 +15,14 @@
         "com.unity.textmeshpro": "2.0.1",
         "com.unity.timeline": "1.2.14"
       },
-      "hash": "799efe48dc0a6990e8a1d7a2372415a11fa8dfbc"
+      "hash": "e61ba2931c7d57926098254e61df7d51488782e6"
     },
     "com.neuecc.unirx": {
       "version": "https://github.com/neuecc/UniRx.git?path=Assets/Plugins/UniRx/Scripts",
       "depth": 0,
       "source": "git",
       "dependencies": {},
-      "hash": "284d5c50d3f1ddd9fa7df3d382ea904732a9c2ff"
+      "hash": "7cce378b3f8c8943b4cac8e847bdbb8e2e1802d1"
     },
     "com.unity.2d.sprite": {
       "version": "1.0.0",
@@ -31,11 +31,11 @@
       "dependencies": {}
     },
     "com.unity.addressables": {
-      "version": "1.17.17",
+      "version": "1.19.19",
       "depth": 0,
       "source": "registry",
       "dependencies": {
-        "com.unity.scriptablebuildpipeline": "1.17.0",
+        "com.unity.scriptablebuildpipeline": "1.19.6",
         "com.unity.modules.assetbundle": "1.0.0",
         "com.unity.modules.imageconversion": "1.0.0",
         "com.unity.modules.jsonserialize": "1.0.0",
@@ -45,7 +45,7 @@
       "url": "https://packages.unity.com"
     },
     "com.unity.collab-proxy": {
-      "version": "1.6.0",
+      "version": "2.0.4",
       "depth": 0,
       "source": "registry",
       "dependencies": {},
@@ -59,16 +59,16 @@
       "url": "https://packages.unity.com"
     },
     "com.unity.ide.rider": {
-      "version": "1.2.1",
+      "version": "3.0.21",
       "depth": 0,
       "source": "registry",
       "dependencies": {
-        "com.unity.test-framework": "1.1.1"
+        "com.unity.ext.nunit": "1.0.6"
       },
       "url": "https://packages.unity.com"
     },
     "com.unity.ide.visualstudio": {
-      "version": "2.0.9",
+      "version": "2.0.18",
       "depth": 0,
       "source": "registry",
       "dependencies": {
@@ -77,21 +77,21 @@
       "url": "https://packages.unity.com"
     },
     "com.unity.ide.vscode": {
-      "version": "1.2.3",
+      "version": "1.2.5",
       "depth": 0,
       "source": "registry",
       "dependencies": {},
       "url": "https://packages.unity.com"
     },
     "com.unity.scriptablebuildpipeline": {
-      "version": "1.17.0",
+      "version": "1.20.1",
       "depth": 1,
       "source": "registry",
       "dependencies": {},
       "url": "https://packages.unity.com"
     },
     "com.unity.test-framework": {
-      "version": "1.1.27",
+      "version": "1.1.31",
       "depth": 0,
       "source": "registry",
       "dependencies": {
@@ -102,7 +102,7 @@
       "url": "https://packages.unity.com"
     },
     "com.unity.textmeshpro": {
-      "version": "2.1.6",
+      "version": "3.0.6",
       "depth": 0,
       "source": "registry",
       "dependencies": {
@@ -111,7 +111,7 @@
       "url": "https://packages.unity.com"
     },
     "com.unity.timeline": {
-      "version": "1.2.18",
+      "version": "1.6.5",
       "depth": 0,
       "source": "registry",
       "dependencies": {
@@ -264,6 +264,18 @@
       "depth": 0,
       "source": "builtin",
       "dependencies": {
+        "com.unity.modules.ui": "1.0.0",
+        "com.unity.modules.imgui": "1.0.0",
+        "com.unity.modules.jsonserialize": "1.0.0",
+        "com.unity.modules.uielementsnative": "1.0.0"
+      }
+    },
+    "com.unity.modules.uielementsnative": {
+      "version": "1.0.0",
+      "depth": 1,
+      "source": "builtin",
+      "dependencies": {
+        "com.unity.modules.ui": "1.0.0",
         "com.unity.modules.imgui": "1.0.0",
         "com.unity.modules.jsonserialize": "1.0.0"
       }
diff --git a/ProjectSettings/MemorySettings.asset b/ProjectSettings/MemorySettings.asset
new file mode 100644
index 0000000..5b5face
--- /dev/null
+++ b/ProjectSettings/MemorySettings.asset
@@ -0,0 +1,35 @@
+%YAML 1.1
+%TAG !u! tag:unity3d.com,2011:
+--- !u!387306366 &1
+MemorySettings:
+  m_ObjectHideFlags: 0
+  m_EditorMemorySettings:
+    m_MainAllocatorBlockSize: -1
+    m_ThreadAllocatorBlockSize: -1
+    m_MainGfxBlockSize: -1
+    m_ThreadGfxBlockSize: -1
+    m_CacheBlockSize: -1
+    m_TypetreeBlockSize: -1
+    m_ProfilerBlockSize: -1
+    m_ProfilerEditorBlockSize: -1
+    m_BucketAllocatorGranularity: -1
+    m_BucketAllocatorBucketsCount: -1
+    m_BucketAllocatorBlockSize: -1
+    m_BucketAllocatorBlockCount: -1
+    m_ProfilerBucketAllocatorGranularity: -1
+    m_ProfilerBucketAllocatorBucketsCount: -1
+    m_ProfilerBucketAllocatorBlockSize: -1
+    m_ProfilerBucketAllocatorBlockCount: -1
+    m_TempAllocatorSizeMain: -1
+    m_JobTempAllocatorBlockSize: -1
+    m_BackgroundJobTempAllocatorBlockSize: -1
+    m_JobTempAllocatorReducedBlockSize: -1
+    m_TempAllocatorSizeGIBakingWorker: -1
+    m_TempAllocatorSizeNavMeshWorker: -1
+    m_TempAllocatorSizeAudioWorker: -1
+    m_TempAllocatorSizeCloudWorker: -1
+    m_TempAllocatorSizeGfx: -1
+    m_TempAllocatorSizeJobWorker: -1
+    m_TempAllocatorSizeBackgroundWorker: -1
+    m_TempAllocatorSizePreloadManager: -1
+  m_PlatformMemorySettings: {}
diff --git a/ProjectSettings/ProjectVersion.txt b/ProjectSettings/ProjectVersion.txt
index ecaedcd..7b416d5 100644
--- a/ProjectSettings/ProjectVersion.txt
+++ b/ProjectSettings/ProjectVersion.txt
@@ -1,2 +1,2 @@
-m_EditorVersion: 2019.4.29f1
-m_EditorVersionWithRevision: 2019.4.29f1 (0eeae20b1d82)
+m_EditorVersion: 2021.3.25f1
+m_EditorVersionWithRevision: 2021.3.25f1 (68ef2c4f8861)
diff --git a/ProjectSettings/VersionControlSettings.asset b/ProjectSettings/VersionControlSettings.asset
new file mode 100644
index 0000000..dca2881
--- /dev/null
+++ b/ProjectSettings/VersionControlSettings.asset
@@ -0,0 +1,8 @@
+%YAML 1.1
+%TAG !u! tag:unity3d.com,2011:
+--- !u!890905787 &1
+VersionControlSettings:
+  m_ObjectHideFlags: 0
+  m_Mode: Visible Meta Files
+  m_CollabEditorSettings:
+    inProgressEnabled: 1
diff --git a/ProjectSettings/boot.config b/ProjectSettings/boot.config
new file mode 100644
index 0000000..e69de29
diff --git a/README.md b/README.md
index 80daefb..a52122f 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ For more information, including copyright, please refer to the following website
 ## Setup
 
 #### Requirement
-* Unity 2019.4 or higher
+* Unity 2021.3 or higher
 * uGUI (UIElements not supported)
 
 #### Install
diff --git a/README_JA.md b/README_JA.md
index 52c5e64..5951a2f 100644
--- a/README_JA.md
+++ b/README_JA.md
@@ -93,7 +93,7 @@ UnityのuGUIで画面遷移、画面遷移アニメーション、遷移履歴
 ## セットアップ
 
 #### 要件
-* Unity 2019.4 以上
+* Unity 2021.3 以上
 * uGUI (UIElementsには非対応)
 
 #### インストール