diff --git a/FDK19/FDK19.csproj b/FDK19/FDK19.csproj
index e160b8b1..b061ac24 100644
--- a/FDK19/FDK19.csproj
+++ b/FDK19/FDK19.csproj
@@ -7,6 +7,7 @@
     <OutputType>Library</OutputType>
     <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
+    <ImplicitUsings>true</ImplicitUsings>
 
     <AssemblyName>FDK</AssemblyName>
     <RootNamespace>FDK</RootNamespace>
@@ -57,6 +58,21 @@
     <AdditionalFiles Include="../BannedSymbols.txt" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Using Include="System.Collections.Concurrent" />
+    <Using Include="System.Collections.Frozen" />
+    <Using Include="System.Collections.ObjectModel" />
+    <Using Include="System.Collections.Specialized" />
+    <Using Include="System.ComponentModel" />
+    <Using Include="System.Diagnostics" />
+    <Using Include="System.Drawing" />
+    <Using Include="System.Numerics" />
+    <Using Include="System.Reflection" />
+    <Using Include="System.Runtime.InteropServices" />
+    <Using Include="System.Text" />
+    <Using Include="System.Xml.XPath" />
+  </ItemGroup>
+
   <PropertyGroup>
     <PackageId>FDKライブラリ</PackageId>
     <Product>FDKライブラリ ver.21</Product>
diff --git a/FDK19/src/00.Common/CActivity.cs b/FDK19/src/00.Common/CActivity.cs
index b6695d88..473bccc4 100644
--- a/FDK19/src/00.Common/CActivity.cs
+++ b/FDK19/src/00.Common/CActivity.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace FDK;
+namespace FDK;
 
 public class CActivity
 {
diff --git a/FDK19/src/00.Common/CCommon.cs b/FDK19/src/00.Common/CCommon.cs
index 91e50cab..b98d9c06 100644
--- a/FDK19/src/00.Common/CCommon.cs
+++ b/FDK19/src/00.Common/CCommon.cs
@@ -1,5 +1,4 @@
-using System;
-using SkiaSharp;
+using SkiaSharp;
 
 namespace FDK;
 
diff --git a/FDK19/src/00.Common/CConvert.cs b/FDK19/src/00.Common/CConvert.cs
index aa5c77de..72f136f0 100644
--- a/FDK19/src/00.Common/CConvert.cs
+++ b/FDK19/src/00.Common/CConvert.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Text;
-using System.Linq;
-
-namespace FDK;
+namespace FDK;
 
 public static class CConvert
 {
diff --git a/FDK19/src/00.Common/CCounter.cs b/FDK19/src/00.Common/CCounter.cs
index b281d0f9..db3d59a5 100644
--- a/FDK19/src/00.Common/CCounter.cs
+++ b/FDK19/src/00.Common/CCounter.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace FDK;
+namespace FDK;
 
 /// <summary>
 /// 一定間隔で単純増加する整数（カウント値）を扱う。
diff --git a/FDK19/src/00.Common/CFPS.cs b/FDK19/src/00.Common/CFPS.cs
index a6d1ec6c..2e5a9466 100644
--- a/FDK19/src/00.Common/CFPS.cs
+++ b/FDK19/src/00.Common/CFPS.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace FDK;
+namespace FDK;
 
 public class CFPS
 {
diff --git a/FDK19/src/00.Common/CJudgeTextEncoding.cs b/FDK19/src/00.Common/CJudgeTextEncoding.cs
index 265957e6..d1dfe556 100644
--- a/FDK19/src/00.Common/CJudgeTextEncoding.cs
+++ b/FDK19/src/00.Common/CJudgeTextEncoding.cs
@@ -1,6 +1,4 @@
-using System.IO;
-
-namespace FDK;
+namespace FDK;
 
 public class CJudgeTextEncoding
 {
diff --git a/FDK19/src/00.Common/COS.cs b/FDK19/src/00.Common/COS.cs
index 6038a989..c5e2fe3a 100644
--- a/FDK19/src/00.Common/COS.cs
+++ b/FDK19/src/00.Common/COS.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace FDK;
+namespace FDK;
 
 public static class COS //2020.05.08 Mr-Ojii DTXManiaからいろいろと移植
 {
diff --git a/FDK19/src/00.Common/CTimer.cs b/FDK19/src/00.Common/CTimer.cs
index 5720ec42..eedad2ea 100644
--- a/FDK19/src/00.Common/CTimer.cs
+++ b/FDK19/src/00.Common/CTimer.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Runtime.InteropServices;
-using System.Diagnostics;
-
-namespace FDK;
+namespace FDK;
 
 public class CTimer : CTimerBase
 {
diff --git a/FDK19/src/00.Common/CTimerBase.cs b/FDK19/src/00.Common/CTimerBase.cs
index 45695935..293cdb36 100644
--- a/FDK19/src/00.Common/CTimerBase.cs
+++ b/FDK19/src/00.Common/CTimerBase.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace FDK;
+namespace FDK;
 
 /// <summary>
 /// <para>タイマの抽象クラス。</para>
diff --git a/FDK19/src/00.Common/CTraceLogListener.cs b/FDK19/src/00.Common/CTraceLogListener.cs
index 3088aec1..cedc47fa 100644
--- a/FDK19/src/00.Common/CTraceLogListener.cs
+++ b/FDK19/src/00.Common/CTraceLogListener.cs
@@ -1,8 +1,4 @@
-using System;
-using System.IO;
-using System.Diagnostics;
-
-namespace FDK;
+namespace FDK;
 
 public class CTraceLogListener : TraceListener
 {
diff --git a/FDK19/src/00.Common/CWebOpen.cs b/FDK19/src/00.Common/CWebOpen.cs
index bd62b542..8b89e341 100644
--- a/FDK19/src/00.Common/CWebOpen.cs
+++ b/FDK19/src/00.Common/CWebOpen.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Diagnostics;
-using System.Runtime.InteropServices;
-
-namespace FDK;
+namespace FDK;
 
 public static class CWebOpen
 {
diff --git a/FDK19/src/01.Framework/Device.cs b/FDK19/src/01.Framework/Device.cs
index 51b7c32e..db9b7759 100644
--- a/FDK19/src/01.Framework/Device.cs
+++ b/FDK19/src/01.Framework/Device.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace FDK;
+namespace FDK;
 
 /// <summary>
 /// 大規模な変更がめんどくさかったために作ったクラス
diff --git a/FDK19/src/01.Framework/Game.cs b/FDK19/src/01.Framework/Game.cs
index ffcd1bff..99f4b31f 100644
--- a/FDK19/src/01.Framework/Game.cs
+++ b/FDK19/src/01.Framework/Game.cs
@@ -1,11 +1,4 @@
-using System;
-using System.ComponentModel;
-using System.Threading;
-using System.Reflection;
-using System.IO;
-using System.Text;
-using System.Runtime.InteropServices;
-using FDK.Windowing;
+using FDK.Windowing;
 
 namespace FDK;
 
diff --git a/FDK19/src/01.Framework/SDL2/GameWindow.cs b/FDK19/src/01.Framework/SDL2/GameWindow.cs
index 0b403071..5e172770 100644
--- a/FDK19/src/01.Framework/SDL2/GameWindow.cs
+++ b/FDK19/src/01.Framework/SDL2/GameWindow.cs
@@ -1,15 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.IO;
-using System.Drawing;
-using System.Diagnostics;
-using System.ComponentModel;
-using System.Runtime.InteropServices;
-using SDL2;
-using FDK;
+using SDL2;
 
 namespace FDK.Windowing;
 
diff --git a/FDK19/src/01.Framework/SDL2/MouseWheelEvent.cs b/FDK19/src/01.Framework/SDL2/MouseWheelEvent.cs
index 76f324b7..b5114587 100644
--- a/FDK19/src/01.Framework/SDL2/MouseWheelEvent.cs
+++ b/FDK19/src/01.Framework/SDL2/MouseWheelEvent.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace FDK.Windowing;
+namespace FDK.Windowing;
 
 public class MouseWheelEventArgs : EventArgs
 {
diff --git a/FDK19/src/01.Framework/SDL2/WindowState.cs b/FDK19/src/01.Framework/SDL2/WindowState.cs
index 26eaaae2..03d2a131 100644
--- a/FDK19/src/01.Framework/SDL2/WindowState.cs
+++ b/FDK19/src/01.Framework/SDL2/WindowState.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace FDK.Windowing;
+namespace FDK.Windowing;
 
 public enum WindowState
 {
diff --git a/FDK19/src/02.Input/CInputJoystick.cs b/FDK19/src/02.Input/CInputJoystick.cs
index f74f30cc..bf9ebc8d 100644
--- a/FDK19/src/02.Input/CInputJoystick.cs
+++ b/FDK19/src/02.Input/CInputJoystick.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Collections.Concurrent;
-using SDL2;
-using System.Runtime.CompilerServices;
+using SDL2;
 
 namespace FDK;
 
diff --git a/FDK19/src/02.Input/CInputKeyboard.cs b/FDK19/src/02.Input/CInputKeyboard.cs
index 2a2194ba..79d0ff8b 100644
--- a/FDK19/src/02.Input/CInputKeyboard.cs
+++ b/FDK19/src/02.Input/CInputKeyboard.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Collections.Concurrent;
-using SDL2;
-
-using SlimDXKey = SlimDXKeys.Key;
+using SDL2;
 
 namespace FDK;
 
diff --git a/FDK19/src/02.Input/CInputMIDI.cs b/FDK19/src/02.Input/CInputMIDI.cs
index 0a264552..4d359826 100644
--- a/FDK19/src/02.Input/CInputMIDI.cs
+++ b/FDK19/src/02.Input/CInputMIDI.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Collections.Concurrent;
-
-namespace FDK;
+namespace FDK;
 
 public class CInputMIDI : IInputDevice, IDisposable
 {
diff --git a/FDK19/src/02.Input/CInputManager.cs b/FDK19/src/02.Input/CInputManager.cs
index f5a4b153..3ad89969 100644
--- a/FDK19/src/02.Input/CInputManager.cs
+++ b/FDK19/src/02.Input/CInputManager.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Linq;
-using System.Diagnostics;
-using System.Runtime.InteropServices;
-using Commons.Music.Midi;
+using Commons.Music.Midi;
 
 namespace FDK;
 
diff --git a/FDK19/src/02.Input/CInputMouse.cs b/FDK19/src/02.Input/CInputMouse.cs
index 07305173..c42b3438 100644
--- a/FDK19/src/02.Input/CInputMouse.cs
+++ b/FDK19/src/02.Input/CInputMouse.cs
@@ -1,7 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Collections.Concurrent;
-using SDL2;
+using SDL2;
 
 namespace FDK;
 
diff --git a/FDK19/src/02.Input/DeviceConstantConverter.cs b/FDK19/src/02.Input/DeviceConstantConverter.cs
index 88b98dcc..40ca339e 100644
--- a/FDK19/src/02.Input/DeviceConstantConverter.cs
+++ b/FDK19/src/02.Input/DeviceConstantConverter.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Collections.Frozen;
-using System.Text;
-
-using SlimDXKey = SlimDXKeys.Key;
+using SlimDXKey = SlimDXKeys.Key;
 using SDLKey = SDL2.SDL.SDL_Scancode;
 
 namespace FDK;
diff --git a/FDK19/src/02.Input/EInputDeviceType.cs b/FDK19/src/02.Input/EInputDeviceType.cs
index 61d562fc..33eda461 100644
--- a/FDK19/src/02.Input/EInputDeviceType.cs
+++ b/FDK19/src/02.Input/EInputDeviceType.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace FDK;
+namespace FDK;
 
 // 定数
 public enum EInputDeviceType
diff --git a/FDK19/src/02.Input/IInputDevice.cs b/FDK19/src/02.Input/IInputDevice.cs
index 8fd86e90..595d2fe1 100644
--- a/FDK19/src/02.Input/IInputDevice.cs
+++ b/FDK19/src/02.Input/IInputDevice.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace FDK;
+namespace FDK;
 
 public interface IInputDevice : IDisposable
 {
diff --git a/FDK19/src/02.Input/STInputEvent.cs b/FDK19/src/02.Input/STInputEvent.cs
index a8a45b9e..fbaa0e5b 100644
--- a/FDK19/src/02.Input/STInputEvent.cs
+++ b/FDK19/src/02.Input/STInputEvent.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Runtime.InteropServices;
-
-namespace FDK;
+namespace FDK;
 
 public enum EInputEventType
 {
diff --git a/FDK19/src/02.Input/SlimDXKeys.cs b/FDK19/src/02.Input/SlimDXKeys.cs
index a8be9fb7..af83749f 100644
--- a/FDK19/src/02.Input/SlimDXKeys.cs
+++ b/FDK19/src/02.Input/SlimDXKeys.cs
@@ -1,11 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using SDL2;
-
-namespace SlimDXKeys;
+namespace SlimDXKeys;
 
 public enum Key
 {
diff --git a/FDK19/src/03.Sound/CAudioDecoder.cs b/FDK19/src/03.Sound/CAudioDecoder.cs
index 6c0aead8..c7f270ee 100644
--- a/FDK19/src/03.Sound/CAudioDecoder.cs
+++ b/FDK19/src/03.Sound/CAudioDecoder.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Buffers;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.IO;
-using System.Runtime.InteropServices;
-using FFmpeg.AutoGen;
+using FFmpeg.AutoGen;
 
 namespace FDK;
 
diff --git a/FDK19/src/03.Sound/CBassLibraryLoader.cs b/FDK19/src/03.Sound/CBassLibraryLoader.cs
index 967306ad..a281d328 100644
--- a/FDK19/src/03.Sound/CBassLibraryLoader.cs
+++ b/FDK19/src/03.Sound/CBassLibraryLoader.cs
@@ -1,12 +1,4 @@
-using System;
-using System.IO;
-using System.Reflection;
-using System.Collections.Generic;
-using System.Text;
-using System.Runtime;
-using System.Runtime.InteropServices;
-
-namespace FDK;
+namespace FDK;
 
 //Linuxでの"BASS must be loaded first"のエラー解消用
 
diff --git a/FDK19/src/03.Sound/CSound.cs b/FDK19/src/03.Sound/CSound.cs
index 76a337f8..73449285 100644
--- a/FDK19/src/03.Sound/CSound.cs
+++ b/FDK19/src/03.Sound/CSound.cs
@@ -1,11 +1,4 @@
-using System;
-using System.Collections.ObjectModel;
-using System.Diagnostics;
-using System.Runtime.InteropServices;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using FDK.BassMixExtension;
+using FDK.BassMixExtension;
 using ManagedBass;
 using ManagedBass.Mix;
 using ManagedBass.Fx;
diff --git a/FDK19/src/03.Sound/CSoundDeviceASIO.cs b/FDK19/src/03.Sound/CSoundDeviceASIO.cs
index 7263ed20..58a38868 100644
--- a/FDK19/src/03.Sound/CSoundDeviceASIO.cs
+++ b/FDK19/src/03.Sound/CSoundDeviceASIO.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Diagnostics;
-using ManagedBass;
+using ManagedBass;
 using ManagedBass.Asio;
 using ManagedBass.Mix;
 
diff --git a/FDK19/src/03.Sound/CSoundDeviceBASS.cs b/FDK19/src/03.Sound/CSoundDeviceBASS.cs
index fc6d6fcb..493ac7fd 100644
--- a/FDK19/src/03.Sound/CSoundDeviceBASS.cs
+++ b/FDK19/src/03.Sound/CSoundDeviceBASS.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Diagnostics;
-using System.Reflection;
-using System.IO;
-using ManagedBass;
+using ManagedBass;
 using ManagedBass.Mix;
 
 namespace FDK;
diff --git a/FDK19/src/03.Sound/CSoundDeviceWASAPI.cs b/FDK19/src/03.Sound/CSoundDeviceWASAPI.cs
index 2c6de517..872b7f81 100644
--- a/FDK19/src/03.Sound/CSoundDeviceWASAPI.cs
+++ b/FDK19/src/03.Sound/CSoundDeviceWASAPI.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Diagnostics;
-using ManagedBass;
+using ManagedBass;
 using ManagedBass.Wasapi;
 using ManagedBass.Mix;
 
diff --git a/FDK19/src/03.Sound/CSoundManager.cs b/FDK19/src/03.Sound/CSoundManager.cs
index 6b798ff4..d6114090 100644
--- a/FDK19/src/03.Sound/CSoundManager.cs
+++ b/FDK19/src/03.Sound/CSoundManager.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Diagnostics;
-using System.IO;
-
-namespace FDK;
+namespace FDK;
 
 #region [ DTXMania用拡張 ]
 public class CSoundManager  // : CSound
diff --git a/FDK19/src/03.Sound/CSoundTimer.cs b/FDK19/src/03.Sound/CSoundTimer.cs
index 965582c4..2a5d8e0d 100644
--- a/FDK19/src/03.Sound/CSoundTimer.cs
+++ b/FDK19/src/03.Sound/CSoundTimer.cs
@@ -1,11 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Threading;
-using System.Runtime.InteropServices;
-using System.Diagnostics;
-
-namespace FDK;
+namespace FDK;
 
 public class CSoundTimer : CTimerBase
 {
diff --git a/FDK19/src/03.Sound/ESoundDeviceType.cs b/FDK19/src/03.Sound/ESoundDeviceType.cs
index 33a2d593..2184c2bb 100644
--- a/FDK19/src/03.Sound/ESoundDeviceType.cs
+++ b/FDK19/src/03.Sound/ESoundDeviceType.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace FDK;
+namespace FDK;
 
 public enum ESoundDeviceType
 {
diff --git a/FDK19/src/03.Sound/ExtensionMethods/BassMixExtensions.cs b/FDK19/src/03.Sound/ExtensionMethods/BassMixExtensions.cs
index 83c55056..e176009d 100644
--- a/FDK19/src/03.Sound/ExtensionMethods/BassMixExtensions.cs
+++ b/FDK19/src/03.Sound/ExtensionMethods/BassMixExtensions.cs
@@ -1,7 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using ManagedBass;
+using ManagedBass;
 using ManagedBass.Mix;
 
 namespace FDK.BassMixExtension;
diff --git a/FDK19/src/03.Sound/ISoundDevice.cs b/FDK19/src/03.Sound/ISoundDevice.cs
index 353838d2..5b005c70 100644
--- a/FDK19/src/03.Sound/ISoundDevice.cs
+++ b/FDK19/src/03.Sound/ISoundDevice.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Diagnostics;
-
-namespace FDK;
+namespace FDK;
 
 internal interface ISoundDevice : IDisposable
 {
diff --git a/FDK19/src/03.Sound/LoudnessMetadata.cs b/FDK19/src/03.Sound/LoudnessMetadata.cs
index 42d72973..d869353e 100644
--- a/FDK19/src/03.Sound/LoudnessMetadata.cs
+++ b/FDK19/src/03.Sound/LoudnessMetadata.cs
@@ -1,6 +1,4 @@
-using System;
-
-namespace FDK;
+namespace FDK;
 
 /// <summary>
 /// The LoudnessMetadata structure is used to carry, and assist with
diff --git a/FDK19/src/03.Sound/LoudnessMetadataScanner.cs b/FDK19/src/03.Sound/LoudnessMetadataScanner.cs
index 67442797..9b3cf073 100644
--- a/FDK19/src/03.Sound/LoudnessMetadataScanner.cs
+++ b/FDK19/src/03.Sound/LoudnessMetadataScanner.cs
@@ -1,13 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using System.Diagnostics;
-using System.IO;
-using System.Linq;
-using System.Threading;
-using System.Xml.XPath;
-
-namespace FDK;
+namespace FDK;
 
 /// <summary>
 /// The LoudnessMetadataScanner plays two roles:
diff --git a/FDK19/src/03.Sound/Lufs.cs b/FDK19/src/03.Sound/Lufs.cs
index c4df42eb..2d239ff8 100644
--- a/FDK19/src/03.Sound/Lufs.cs
+++ b/FDK19/src/03.Sound/Lufs.cs
@@ -1,6 +1,4 @@
-using System;
-
-namespace FDK;
+namespace FDK;
 
 /// <summary>
 /// The Lufs structure is used to carry, and assist with calculations related to,
diff --git a/FDK19/src/03.Sound/SoundGroupLevelController.cs b/FDK19/src/03.Sound/SoundGroupLevelController.cs
index b0a5686d..fc9b728e 100644
--- a/FDK19/src/03.Sound/SoundGroupLevelController.cs
+++ b/FDK19/src/03.Sound/SoundGroupLevelController.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Collections.Specialized;
-
-namespace FDK;
+namespace FDK;
 
 /// <summary>
 /// SoundGroupLevelController holds the current sound level value for each
diff --git a/FDK19/src/04.Graphic/CDecodedFrame.cs b/FDK19/src/04.Graphic/CDecodedFrame.cs
index 660f7012..28f4bf75 100644
--- a/FDK19/src/04.Graphic/CDecodedFrame.cs
+++ b/FDK19/src/04.Graphic/CDecodedFrame.cs
@@ -1,11 +1,4 @@
-using System;
-using System.Drawing;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Runtime.InteropServices;
-using FFmpeg.AutoGen;
+using FFmpeg.AutoGen;
 
 namespace FDK;
 
diff --git a/FDK19/src/04.Graphic/CFrameConverter.cs b/FDK19/src/04.Graphic/CFrameConverter.cs
index 224a1d4a..09d223b1 100644
--- a/FDK19/src/04.Graphic/CFrameConverter.cs
+++ b/FDK19/src/04.Graphic/CFrameConverter.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Drawing;
-using System.Text;
-using System.Runtime.InteropServices;
-using FFmpeg.AutoGen;
+using FFmpeg.AutoGen;
 
 
 namespace FDK;
diff --git a/FDK19/src/04.Graphic/CTexture.cs b/FDK19/src/04.Graphic/CTexture.cs
index d965b925..b73b19eb 100644
--- a/FDK19/src/04.Graphic/CTexture.cs
+++ b/FDK19/src/04.Graphic/CTexture.cs
@@ -1,12 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Drawing;
-using System.Buffers;
-using System.IO;
-using System.Diagnostics;
-using System.Numerics;
-using SDL2;
+using SDL2;
 using SkiaSharp;
 
 using Rectangle = System.Drawing.Rectangle;
diff --git a/FDK19/src/04.Graphic/CTextureCreateFailedException.cs b/FDK19/src/04.Graphic/CTextureCreateFailedException.cs
index 6bb1a8fc..04fd3cf5 100644
--- a/FDK19/src/04.Graphic/CTextureCreateFailedException.cs
+++ b/FDK19/src/04.Graphic/CTextureCreateFailedException.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Runtime.Serialization;
-
-namespace FDK;
+namespace FDK;
 
 /// <summary>
 /// テクスチャの作成に失敗しました。
diff --git a/FDK19/src/04.Graphic/CVideoDecoder.cs b/FDK19/src/04.Graphic/CVideoDecoder.cs
index c160972d..fc76aa11 100644
--- a/FDK19/src/04.Graphic/CVideoDecoder.cs
+++ b/FDK19/src/04.Graphic/CVideoDecoder.cs
@@ -1,15 +1,4 @@
-using System;
-using System.IO;
-using System.Diagnostics;
-using System.Collections.Generic;
-using System.Drawing;
-using System.Runtime.InteropServices;
-using System.Collections.Concurrent;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using FFmpeg.AutoGen;
-using System.Threading;
+using FFmpeg.AutoGen;
 
 using Size = System.Drawing.Size;
 using SkiaSharp;
diff --git a/FDK19/src/04.Graphic/TextRenderer/CCachedFontRenderer.cs b/FDK19/src/04.Graphic/TextRenderer/CCachedFontRenderer.cs
index 5c57c174..c70f7b0a 100644
--- a/FDK19/src/04.Graphic/TextRenderer/CCachedFontRenderer.cs
+++ b/FDK19/src/04.Graphic/TextRenderer/CCachedFontRenderer.cs
@@ -1,7 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using SkiaSharp;
+using SkiaSharp;
 
 using Color = System.Drawing.Color;
 
diff --git a/FDK19/src/04.Graphic/TextRenderer/CFontRenderer.cs b/FDK19/src/04.Graphic/TextRenderer/CFontRenderer.cs
index d1170a14..41ece804 100644
--- a/FDK19/src/04.Graphic/TextRenderer/CFontRenderer.cs
+++ b/FDK19/src/04.Graphic/TextRenderer/CFontRenderer.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Diagnostics;
-using System.Linq;
-using System.Reflection;
-using System.Runtime.InteropServices;
-using SkiaSharp;
+using SkiaSharp;
 
 using Color = System.Drawing.Color;
 
diff --git a/FDK19/src/04.Graphic/TextRenderer/CSkiaSharpTextRenderer.cs b/FDK19/src/04.Graphic/TextRenderer/CSkiaSharpTextRenderer.cs
index 413d08bb..45b5364b 100644
--- a/FDK19/src/04.Graphic/TextRenderer/CSkiaSharpTextRenderer.cs
+++ b/FDK19/src/04.Graphic/TextRenderer/CSkiaSharpTextRenderer.cs
@@ -1,8 +1,4 @@
-using System;
-using System.IO;
-using System.Linq;
-using System.Drawing;
-using SkiaSharp;
+using SkiaSharp;
 
 using Color = System.Drawing.Color;
 
diff --git a/FDK19/src/04.Graphic/TextRenderer/ITextRenderer.cs b/FDK19/src/04.Graphic/TextRenderer/ITextRenderer.cs
index e2a6b342..cd07296c 100644
--- a/FDK19/src/04.Graphic/TextRenderer/ITextRenderer.cs
+++ b/FDK19/src/04.Graphic/TextRenderer/ITextRenderer.cs
@@ -1,5 +1,4 @@
-using System;
-using SkiaSharp;
+using SkiaSharp;
 
 using Color = System.Drawing.Color;