diff --git a/Packages/nadena.dev.modular-avatar/Editor/ApplyOnPlay.cs b/Packages/nadena.dev.modular-avatar/Editor/ApplyOnPlay.cs
index 99b5f598..81737ddd 100644
--- a/Packages/nadena.dev.modular-avatar/Editor/ApplyOnPlay.cs
+++ b/Packages/nadena.dev.modular-avatar/Editor/ApplyOnPlay.cs
@@ -23,6 +23,9 @@
  */
 
 using UnityEditor;
+using UnityEngine;
+using UnityEngine.SceneManagement;
+using VRC.SDK3.Avatars.Components;
 
 namespace nadena.dev.modular_avatar.core.editor
 {
@@ -45,10 +48,10 @@ namespace nadena.dev.modular_avatar.core.editor
         {
             EditorApplication.playModeStateChanged += OnPlayModeStateChanged;
             RuntimeUtil.OnDemandProcessAvatar = MaybeProcessAvatar;
-            Menu.SetChecked(MENU_NAME, ModularAvatarSettings.applyOnPlay);
+            EditorApplication.delayCall += () => Menu.SetChecked(MENU_NAME, ModularAvatarSettings.applyOnPlay);
         }
 
-        private static void MaybeProcessAvatar(RuntimeUtil.OnDemandSource source, AvatarTagComponent component)
+        private static void MaybeProcessAvatar(RuntimeUtil.OnDemandSource source, MonoBehaviour component)
         {
             if (ModularAvatarSettings.applyOnPlay && source == armedSource && component != null)
             {
diff --git a/Packages/nadena.dev.modular-avatar/Editor/AvatarProcessor.cs b/Packages/nadena.dev.modular-avatar/Editor/AvatarProcessor.cs
index 3ed54d4e..78622461 100644
--- a/Packages/nadena.dev.modular-avatar/Editor/AvatarProcessor.cs
+++ b/Packages/nadena.dev.modular-avatar/Editor/AvatarProcessor.cs
@@ -172,6 +172,12 @@ namespace nadena.dev.modular_avatar.core.editor
                 {
                     UnityEngine.Object.DestroyImmediate(component);
                 }
+
+                var activator = avatarGameObject.GetComponent<AvatarActivator>();
+                if (activator != null)
+                {
+                    UnityEngine.Object.DestroyImmediate(activator);
+                }
             }
         }
 
diff --git a/Packages/nadena.dev.modular-avatar/Runtime/Activator.cs b/Packages/nadena.dev.modular-avatar/Runtime/Activator.cs
new file mode 100644
index 00000000..2894555f
--- /dev/null
+++ b/Packages/nadena.dev.modular-avatar/Runtime/Activator.cs
@@ -0,0 +1,119 @@
+#if UNITY_EDITOR
+
+using System;
+using UnityEditor;
+using UnityEditor.SceneManagement;
+using UnityEngine;
+using UnityEngine.SceneManagement;
+using VRC.SDK3.Avatars.Components;
+
+namespace nadena.dev.modular_avatar.core
+{
+    /// <summary>
+    /// This component is used to trigger MA processing upon entering play mode (prior to Av3Emu running).
+    /// We create it on a hidden object via AvatarTagObject's OnValidate, and it will proceed to add MAAvatarActivator
+    /// components to all avatar roots which contain MA components. This MAAvatarActivator component then performs MA
+    /// processing on Awake.
+    ///
+    /// Note that we do not directly process the avatars from MAActivator. This is to avoid processing avatars that are
+    /// initially inactive in the scene (which can have high overhead if the user has a lot of inactive avatars in the
+    /// scene).
+    /// </summary>
+    [AddComponentMenu("")]
+    [ExecuteInEditMode]
+    [DefaultExecutionOrder(-9998)]
+    public class Activator : MonoBehaviour
+    {
+        private const string TAG_OBJECT_NAME = "ModularAvatarInternal_Activator";
+
+        private void Awake()
+        {
+            if (!RuntimeUtil.isPlaying || this == null) return;
+
+            var scene = gameObject.scene;
+            foreach (var root in scene.GetRootGameObjects())
+            {
+                foreach (var avatar in root.GetComponentsInChildren<VRCAvatarDescriptor>())
+                {
+                    if (avatar.GetComponentInChildren<AvatarTagComponent>(true) != null)
+                    {
+                        avatar.gameObject.GetOrAddComponent<AvatarActivator>().hideFlags = HideFlags.HideInInspector;
+                    }
+                }
+            }
+        }
+
+        private bool HasMAComponentsInScene()
+        {
+            var scene = gameObject.scene;
+            foreach (var root in scene.GetRootGameObjects())
+            {
+                if (root.GetComponentInChildren<AvatarTagComponent>(true) != null) return true;
+            }
+
+            return false;
+        }
+
+        private void OnValidate()
+        {
+            EditorApplication.delayCall += () =>
+            {
+                gameObject.hideFlags = HideFlags.HideInHierarchy;
+                if (!HasMAComponentsInScene())
+                {
+                    var scene = gameObject.scene;
+                    DestroyImmediate(gameObject);
+                    EditorSceneManager.MarkSceneDirty(scene);
+                }
+            };
+        }
+
+        internal static void CreateIfNotPresent(Scene scene)
+        {
+            if (!scene.IsValid() || EditorSceneManager.IsPreviewScene(scene)) return;
+            if (EditorApplication.isPlayingOrWillChangePlaymode) return;
+
+            foreach (var root in scene.GetRootGameObjects())
+            {
+                if (root.GetComponent<Activator>() != null) return;
+            }
+
+            var oldActiveScene = SceneManager.GetActiveScene();
+            try
+            {
+                SceneManager.SetActiveScene(scene);
+                var gameObject = new GameObject(TAG_OBJECT_NAME);
+                gameObject.AddComponent<Activator>();
+                gameObject.hideFlags = HideFlags.HideInHierarchy;
+            }
+            finally
+            {
+                SceneManager.SetActiveScene(oldActiveScene);
+            }
+        }
+    }
+
+    [AddComponentMenu("")]
+    [ExecuteInEditMode]
+    [DefaultExecutionOrder(-9997)]
+    public class AvatarActivator : MonoBehaviour
+    {
+        private void Awake()
+        {
+            if (!RuntimeUtil.isPlaying || this == null) return;
+            RuntimeUtil.OnDemandProcessAvatar(RuntimeUtil.OnDemandSource.Awake, this);
+        }
+
+        private void Start()
+        {
+            if (!RuntimeUtil.isPlaying || this == null) return;
+            RuntimeUtil.OnDemandProcessAvatar(RuntimeUtil.OnDemandSource.Start, this);
+        }
+
+        private void Update()
+        {
+            DestroyImmediate(this);
+        }
+    }
+}
+#endif
\ No newline at end of file
diff --git a/Packages/nadena.dev.modular-avatar/Runtime/Activator.cs.meta b/Packages/nadena.dev.modular-avatar/Runtime/Activator.cs.meta
new file mode 100644
index 00000000..1254fa5f
--- /dev/null
+++ b/Packages/nadena.dev.modular-avatar/Runtime/Activator.cs.meta
@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: e41c5d0c41074360bc33887977722a4d
+timeCreated: 1671337621
\ No newline at end of file
diff --git a/Packages/nadena.dev.modular-avatar/Runtime/AvatarTagComponent.cs b/Packages/nadena.dev.modular-avatar/Runtime/AvatarTagComponent.cs
index 1f7cc400..a4e1141e 100644
--- a/Packages/nadena.dev.modular-avatar/Runtime/AvatarTagComponent.cs
+++ b/Packages/nadena.dev.modular-avatar/Runtime/AvatarTagComponent.cs
@@ -22,7 +22,6 @@
  * SOFTWARE.
  */
 
-using System;
 using UnityEngine;
 
 namespace nadena.dev.modular_avatar.core
@@ -44,5 +43,18 @@ namespace nadena.dev.modular_avatar.core
             if (!RuntimeUtil.isPlaying || this == null) return;
             RuntimeUtil.OnDemandProcessAvatar(RuntimeUtil.OnDemandSource.Start, this);
         }
+
+        private void OnValidate()
+        {
+            if (RuntimeUtil.isPlaying) return;
+
+            RuntimeUtil.delayCall(() =>
+            {
+                if (this == null) return;
+#if UNITY_EDITOR
+                Activator.CreateIfNotPresent(gameObject.scene);
+#endif
+            });
+        }
     }
 }
\ No newline at end of file
diff --git a/Packages/nadena.dev.modular-avatar/Runtime/RuntimeUtil.cs b/Packages/nadena.dev.modular-avatar/Runtime/RuntimeUtil.cs
index b5b38f7e..529000ce 100644
--- a/Packages/nadena.dev.modular-avatar/Runtime/RuntimeUtil.cs
+++ b/Packages/nadena.dev.modular-avatar/Runtime/RuntimeUtil.cs
@@ -49,7 +49,7 @@ namespace nadena.dev.modular_avatar.core
             Start
         }
 
-        public delegate void OnDemandProcessAvatarDelegate(OnDemandSource source, AvatarTagComponent component);
+        public delegate void OnDemandProcessAvatarDelegate(OnDemandSource source, MonoBehaviour component);
 
         public static OnDemandProcessAvatarDelegate OnDemandProcessAvatar = (_m, _c) => { };