diff --git a/src/sdlmain.cpp b/src/sdlmain.cpp
index 052ba15..a28ff46 100644
--- a/src/sdlmain.cpp
+++ b/src/sdlmain.cpp
@@ -34,6 +34,7 @@ int main(int argc, char *argv[])
 
 	SDL_Init(SDL_INIT_VIDEO);
 	SDL_SetHint(SDL_HINT_TOUCH_MOUSE_EVENTS, "0");
+	SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
 #ifdef __EMSCRIPTEN__
 	// Stop SDL from calling emscripten_sleep() in functions that are called
 	// indirectly, which does not work with ASYNCIFY_IGNORE_INDIRECT=1. For
diff --git a/src/sys/ags.cpp b/src/sys/ags.cpp
index 53a9adb..cd0d1c7 100644
--- a/src/sys/ags.cpp
+++ b/src/sys/ags.cpp
@@ -40,16 +40,17 @@ AGS::AGS(NACT* parent, const Config& config) : nact(parent), dirty(false)
 {
 	// 画面サイズ
 	if (nact->crc32_a == CRC32_GAKUEN || nact->crc32_a == CRC32_GAKUEN_ENG) {
+		window_width = 582;
 		screen_width = 512;
-		screen_height = 424;
+		window_height = screen_height = 424;
 	} else {
-		screen_width = 640;
-		screen_height = 400;
+		window_width = screen_width = 640;
+		window_height = screen_height = 400;
 	}
 	scroll = screen_height;
 
-	SDL_SetWindowSize(g_window, screen_width, screen_height);
-	SDL_RenderSetLogicalSize(g_renderer, screen_width, screen_height);
+	SDL_SetWindowSize(g_window, window_width, window_height);
+	SDL_RenderSetLogicalSize(g_renderer, window_width, window_height);
 	sdlTexture = SDL_CreateTexture(g_renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STATIC, screen_width, screen_height); // TOOD: pixelformat?
 
 	// DIBSection 8bpp * 3 (表, 裏, メニュー)
diff --git a/src/sys/ags.h b/src/sys/ags.h
index 2887c8b..e5c4102 100644
--- a/src/sys/ags.h
+++ b/src/sys/ags.h
@@ -141,6 +141,7 @@ public:
 	int dest_screen;
 
 	int scroll;
+	int window_width, window_height;
 	int screen_width, screen_height;
 
 	// メッセージ表示
diff --git a/src/sys/nact_input.cpp b/src/sys/nact_input.cpp
index 1536255..db1b41b 100644
--- a/src/sys/nact_input.cpp
+++ b/src/sys/nact_input.cpp
@@ -45,8 +45,8 @@ void NACT::pump_events()
 			break;
 
 		case SDL_MOUSEMOTION:
-			mousex = e.motion.x;
-			mousey = e.motion.y;
+			mousex = e.motion.x * ags->screen_width / ags->window_width;
+			mousey = e.motion.y * ags->screen_height / ags->window_height;
 			break;
 
 		case SDL_FINGERDOWN: