diff --git a/README.md b/README.md
index fc5332f..0cc1e10 100644
--- a/README.md
+++ b/README.md
@@ -55,6 +55,7 @@ This template contains the following:
 | [Cinemachine](https://docs.unity3d.com/Packages/com.unity.cinemachine@latest)                    | Advanced camera system for dynamic shots.                 |
 | [Physics](https://docs.unity3d.com/Manual/PhysicsSection.html)                                   | Physics simulation for 2D and 3D games.                   |
 | [ProBuilder](https://docs.unity3d.com/Packages/com.unity.probuilder@latest)                      | 3D modeling and level design toolset.                     |
+| [R3](https://github.com/Cysharp/R3)                                                              | Reactive Extensions for Unity with ReactiveProperty.       |
 | [Rendering: Post-Processing](https://docs.unity3d.com/Packages/com.unity.postprocessing@latest)  | Visual effects like color grading and bloom.              |
 | [Rendering: URP](https://docs.unity3d.com/Packages/com.unity.render-pipelines.universal@latest)  | Efficient rendering pipeline for various platforms.       |
 | [Text Mesh Pro](https://docs.unity3d.com/Packages/com.unity.textmeshpro@latest)                  | High-quality text rendering and formatting.               |
diff --git a/Unity/Assets/Scripts/Runtime/RMC/[MyProject]/Scenes/Scene01_Intro.cs b/Unity/Assets/Scripts/Runtime/RMC/[MyProject]/Scenes/Scene01_Intro.cs
index 9d1220a..8ba4208 100644
--- a/Unity/Assets/Scripts/Runtime/RMC/[MyProject]/Scenes/Scene01_Intro.cs
+++ b/Unity/Assets/Scripts/Runtime/RMC/[MyProject]/Scenes/Scene01_Intro.cs
@@ -1,4 +1,5 @@
 using System.Threading.Tasks;
+using R3;
 using RMC.Audio;
 using RMC.MyProject.UI;
 using UnityEngine;
@@ -33,6 +34,9 @@ public int Score
             {
                 _score = value;
                 HudUI.ScoreLabel.text = $"Score: {_score:000}/{ScoreMax:000}";
+                
+                // R3 ReactiveProperty demonstration - Update reactive property when score changes
+                _reactiveScore.Value = _score;
             }
         }
         
@@ -107,6 +111,9 @@ private set
         private bool _isEnabledInput = true;
         private bool _isPlayerGrounded = false;
 
+        // R3 ReactiveProperty demonstration
+        private ReactiveProperty<int> _reactiveScore = new ReactiveProperty<int>(0);
+
         // Audio
         private const string PlayerResetAudioClip = "ItemRead01";
         private const string GameWinAudioClip = "Music_Win01";
@@ -122,6 +129,12 @@ protected void Start()
         {
             Debug.Log($"{GetType().Name}.Start()");
             
+            // R3 ReactiveProperty demonstration - Subscribe to value changes
+            _reactiveScore.Subscribe(value => 
+            {
+                Debug.Log($"[R3 Demo] ReactiveScore changed to: {value}");
+            });
+            
             // Input
             _movePlayerInputAction = InputSystem.actions.FindAction("MovePlayer");
             _jumpPlayerInputAction = InputSystem.actions.FindAction("JumpPlayer");
@@ -134,6 +147,9 @@ protected void Start()
             Lives = LivesMax;
             SetInstructions();
             SetTitle();
+            
+            // R3 ReactiveProperty demonstration - Set initial value to trigger subscription
+            _reactiveScore.Value = 1;
         }
 
         /// <summary>
diff --git a/Unity/Packages/manifest.json b/Unity/Packages/manifest.json
index 07cc287..9016856 100644
--- a/Unity/Packages/manifest.json
+++ b/Unity/Packages/manifest.json
@@ -1,5 +1,6 @@
 {
   "dependencies": {
+    "com.cysharp.r3": "https://github.com/Cysharp/R3.git?path=src/R3.Unity/Assets/R3.Unity",
     "com.rmc.rmc-audio": "1.8.4",
     "com.rmc.rmc-core": "1.9.5",
     "com.rmc.rmc-readme": "1.2.2",