diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 0e68eb4..1f2fa4a 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -137,6 +137,7 @@ endif()
 
 target_sources(system3 PRIVATE
   sdlmain.cpp
+  config.cpp
   fileio.cpp
   resource.cpp
   utfsjis.cpp
diff --git a/src/android/mako.cpp b/src/android/mako.cpp
index 0abef4b..5a57166 100644
--- a/src/android/mako.cpp
+++ b/src/android/mako.cpp
@@ -1,6 +1,7 @@
 #include <memory>
 #include <SDL.h>
 #include <android/log.h>
+#include "../config.h"
 #include "jnihelper.h"
 #include "dri.h"
 #include "mako.h"
@@ -23,7 +24,7 @@ void audio_callback(void*, Uint8* stream, int len) {
 
 } // namespace
 
-MAKO::MAKO(NACT* parent, const MAKOConfig& config) :
+MAKO::MAKO(NACT* parent, const Config& config) :
 	use_fm(config.use_fm),
 	current_music(0),
 	next_loop(0),
diff --git a/src/config.cpp b/src/config.cpp
new file mode 100644
index 0000000..42fc87a
--- /dev/null
+++ b/src/config.cpp
@@ -0,0 +1,28 @@
+#include "config.h"
+
+#include <string.h>
+#ifdef _WIN32
+#include <direct.h>
+#else
+#include <unistd.h>
+#endif
+
+Config::Config(int argc, char *argv[])
+{
+	for (int i = 1; i < argc; i++) {
+		if (strcmp(argv[i], "-gamedir") == 0)
+			chdir(argv[++i]);
+		else if (strcmp(argv[i], "-noantialias") == 0)
+			no_antialias = true;
+		else if (strcmp(argv[i], "-savedir") == 0)
+			save_dir = argv[++i];
+		else if (strcmp(argv[i], "-fontfile") == 0)
+			font_file = argv[++i];
+		else if (strcmp(argv[i], "-playlist") == 0)
+			playlist = argv[++i];
+		else if (strcmp(argv[i], "-fm") == 0)
+			use_fm = true;
+		else if (strcmp(argv[i], "-game") == 0)
+			game_id = argv[++i];
+	}
+}
diff --git a/src/config.h b/src/config.h
new file mode 100644
index 0000000..c871fbf
--- /dev/null
+++ b/src/config.h
@@ -0,0 +1,18 @@
+#ifndef CONFIG_H_
+#define CONFIG_H_
+
+#include <string>
+
+struct Config {
+ public:
+	std::string font_file;
+	std::string game_id;
+	std::string save_dir;
+	std::string playlist;
+	bool use_fm = false;
+	bool no_antialias = false;
+
+	Config(int argc, char *argv[]);
+};
+
+#endif // CONFIG_H_
diff --git a/src/emscripten/mako.cpp b/src/emscripten/mako.cpp
index 143e24d..76b64b8 100644
--- a/src/emscripten/mako.cpp
+++ b/src/emscripten/mako.cpp
@@ -16,7 +16,7 @@ std::unique_ptr<MakoFMgen> fm;
 
 } // namespace
 
-MAKO::MAKO(NACT* parent, const MAKOConfig& config) :
+MAKO::MAKO(NACT* parent, const Config& config) :
 	use_fm(true),
 	current_music(0),
 	next_loop(0),
diff --git a/src/linux/mako.cpp b/src/linux/mako.cpp
index 4737e70..4e23c46 100644
--- a/src/linux/mako.cpp
+++ b/src/linux/mako.cpp
@@ -11,6 +11,7 @@
 #include "mako.h"
 #include "mako_midi.h"
 #include "fm/mako_fmgen.h"
+#include "../config.h"
 #include "dri.h"
 
 // MIX_INIT_FLUIDSYNTH was renamed to MIX_INIT_MID in SDL_mixer 2.0.2
@@ -36,7 +37,7 @@ void FMHook(void *udata, Uint8 *stream, int len) {
 
 } // namespace
 
-MAKO::MAKO(NACT* parent, const MAKOConfig& config) :
+MAKO::MAKO(NACT* parent, const Config& config) :
 	use_fm(config.use_fm),
 	current_music(0),
 	next_loop(0),
@@ -44,7 +45,7 @@ MAKO::MAKO(NACT* parent, const MAKOConfig& config) :
 {
 	int mix_init_flags = MIX_INIT_MID;
 
-	if (config.playlist && load_playlist(config.playlist))
+	if (!config.playlist.empty() && load_playlist(config.playlist.c_str()))
 		mix_init_flags |= MIX_INIT_MP3 | MIX_INIT_OGG;
 
 	strcpy_s(amus, 16, "AMUS.DAT");
diff --git a/src/sdlmain.cpp b/src/sdlmain.cpp
index 81c0a1e..105dd8f 100644
--- a/src/sdlmain.cpp
+++ b/src/sdlmain.cpp
@@ -1,12 +1,13 @@
 #include <string>
 #include "common.h"
+#include "config.h"
 #include "fileio.h"
 #include "sys/nact.h"
-#include "sys/mako.h"
 #ifdef _WIN32
 #include <direct.h>
 #else
-#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #endif
 #ifdef __EMSCRIPTEN__
 #include <emscripten.h>
@@ -17,8 +18,9 @@ SDL_Window* g_window;
 
 int main(int argc, char *argv[])
 {
-	SDL_Init(SDL_INIT_VIDEO);
+	Config config(argc, argv);
 
+	SDL_Init(SDL_INIT_VIDEO);
 #ifdef __EMSCRIPTEN__
 	// Stop SDL from calling emscripten_sleep() in functions that are called
 	// indirectly, which does not work with ASYNCIFY_IGNORE_INDIRECT=1. For
@@ -33,33 +35,11 @@ int main(int argc, char *argv[])
 #endif
 	g_window = SDL_CreateWindow("Scenario Decoder SYSTEM3", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 400, flags);
 
-	const char* font_file = NULL;
-	MAKOConfig mako_config;
-	const char* game_id = NULL;
-	const char* save_dir = NULL;
-
-	for (int i = 1; i < argc; i++) {
-		if (strcmp(argv[i], "-gamedir") == 0)
-			chdir(argv[++i]);
-		else if (strcmp(argv[i], "-noantialias") == 0)
-			ags_setAntialiasedStringMode(0);
-		else if (strcmp(argv[i], "-savedir") == 0)
-			save_dir = argv[++i];
-		else if (strcmp(argv[i], "-fontfile") == 0)
-			font_file = argv[++i];
-		else if (strcmp(argv[i], "-playlist") == 0)
-			mako_config.playlist = argv[++i];
-		else if (strcmp(argv[i], "-fm") == 0)
-			mako_config.use_fm = true;
-		else if (strcmp(argv[i], "-game") == 0)
-			game_id = argv[++i];
-	}
-
 	// system3 初期化
-	NACT* nact = NACT::create(game_id, font_file, mako_config);
+	NACT* nact = NACT::create(config);
 
-	if (save_dir && save_dir[0]) {
-		std::string path(save_dir);
+	if (!config.save_dir.empty()) {
+		std::string path = config.save_dir;
 		if (path[path.size() - 1] == '@') {
 			path.pop_back();
 			const char* gid = nact->get_game_id();
@@ -100,7 +80,7 @@ int main(int argc, char *argv[])
 		restart = nact->mainloop();
 		delete nact;
 		if (restart)
-			nact = NACT::create(game_id, font_file, mako_config);
+			nact = NACT::create(config);
 	}
 
 	SDL_DestroyWindow(g_window);
diff --git a/src/sys/ags.cpp b/src/sys/ags.cpp
index 00a8a02..1fe4130 100644
--- a/src/sys/ags.cpp
+++ b/src/sys/ags.cpp
@@ -7,6 +7,7 @@
 #include "ags.h"
 #include <string.h>
 #include "crc32.h"
+#include "../config.h"
 #include "../fileio.h"
 
 extern SDL_Window* g_window;
@@ -34,7 +35,7 @@ static SDL_Surface* display_surface;
 	box[n].ey = y2; \
 }
 
-AGS::AGS(NACT* parent, const char* fontfile) : nact(parent), dirty(false)
+AGS::AGS(NACT* parent, const Config& config) : nact(parent), dirty(false)
 {
 	sdlRenderer = SDL_CreateRenderer(g_window, -1, 0);
 	SDL_RenderSetLogicalSize(sdlRenderer, 640, 400);
@@ -61,10 +62,10 @@ AGS::AGS(NACT* parent, const char* fontfile) : nact(parent), dirty(false)
 
 	// フォント
 	TTF_Init();
-	if (fontfile) {
-		rw_font = SDL_RWFromFile(fontfile, "rb");
+	if (!config.font_file.empty()) {
+		rw_font = SDL_RWFromFile(config.font_file.c_str(), "rb");
 		if (!rw_font)
-			parent->fatal("Cannot open font file %s", fontfile);
+			parent->fatal("Cannot open font file %s", config.font_file.c_str());
 	} else {
 		rw_font = open_resource(FONT_RESOURCE_NAME, "fonts");
 		if (!rw_font)
@@ -84,6 +85,8 @@ AGS::AGS(NACT* parent, const char* fontfile) : nact(parent), dirty(false)
 			parent->fatal("TTF_OpenFontRW failed: %s", TTF_GetError());
 		}
 	}
+	if (config.no_antialias)
+		ags_setAntialiasedStringMode(0);
 
 	// カーソル初期化
 	for(int i = 0; i < 10; i++) {
diff --git a/src/sys/ags.h b/src/sys/ags.h
index 260b6d7..43785b0 100644
--- a/src/sys/ags.h
+++ b/src/sys/ags.h
@@ -36,6 +36,8 @@ inline uint32* surface_line(SDL_Surface* surface, int y)
 	return (uint32*)((uint8*)surface->pixels + surface->pitch * y);
 }
 
+struct Config;
+
 class AGS
 {
 protected:
@@ -91,7 +93,7 @@ private:
 	uint32 fader_screen[640 * 480];
 
 public:
-	AGS(NACT* parent, const char* fontfile);
+	AGS(NACT* parent, const Config& config);
 	~AGS();
 
 	void update_screen();
@@ -221,4 +223,6 @@ public:
 	int cursor_index;
 };
 
+extern "C" void ags_setAntialiasedStringMode(int on);
+
 #endif
diff --git a/src/sys/mako.h b/src/sys/mako.h
index 2995893..708a99d 100644
--- a/src/sys/mako.h
+++ b/src/sys/mako.h
@@ -20,15 +20,12 @@ enum BGMDevice {
 	BGM_CD
 };
 
-struct MAKOConfig {
-	const char *playlist = nullptr;
-	bool use_fm = false;
-};
+struct Config;
 
 class MAKO
 {
 public:
-	MAKO(NACT* parent, const MAKOConfig& config);
+	MAKO(NACT* parent, const Config& config);
 	~MAKO();
 
 	void play_music(int page);
diff --git a/src/sys/nact.cpp b/src/sys/nact.cpp
index 71d6b18..06d809d 100644
--- a/src/sys/nact.cpp
+++ b/src/sys/nact.cpp
@@ -10,6 +10,7 @@
 #include "mako.h"
 #include "msgskip.h"
 #include "dri.h"
+#include "../config.h"
 #include "../fileio.h"
 #include "crc32.h"
 
@@ -17,7 +18,7 @@ extern SDL_Window* g_window;
 
 // 初期化
 
-NACT::NACT(int sys_ver, uint32 crc32_a, uint32 crc32_b, const char* font_file, const MAKOConfig& mako_config)
+NACT::NACT(int sys_ver, uint32 crc32_a, uint32 crc32_b, const Config& config)
 	: sys_ver(sys_ver), crc32_a(crc32_a), crc32_b(crc32_b), lang(get_language())
 {
 	platform_initialize();
@@ -84,8 +85,8 @@ NACT::NACT(int sys_ver, uint32 crc32_a, uint32 crc32_b, const char* font_file, c
 	memset(pcm, 0, sizeof(pcm));
 
 	// 各種クラス生成
-	ags = new AGS(this, font_file);
-	mako = new MAKO(this, mako_config);
+	ags = new AGS(this, config);
+	mako = new MAKO(this, config);
 	msgskip = new MsgSkip(this);
 
 #ifdef USE_JOY
@@ -538,16 +539,16 @@ void NACT::fatal(const char* format, ...) {
 	fatal_error = true;
 }
 
-NACT* NACT::create(const char* game_id, const char* font_file, const MAKOConfig& mako_config) {
-	uint32 crc32_a = NACT::calc_crc32("ADISK.DAT", game_id);
-	uint32 crc32_b = NACT::calc_crc32("BDISK.DAT", game_id);
+NACT* NACT::create(const Config& config) {
+	uint32 crc32_a = NACT::calc_crc32("ADISK.DAT", config.game_id);
+	uint32 crc32_b = NACT::calc_crc32("BDISK.DAT", config.game_id);
 	int sys_ver = NACT::get_sys_ver(crc32_a, crc32_b);
 	switch (sys_ver) {
 	case 1:
-		return new NACT_Sys1(crc32_a, crc32_b, font_file, mako_config);
+		return new NACT_Sys1(crc32_a, crc32_b, config);
 	case 2:
-		return new NACT_Sys2(crc32_a, crc32_b, font_file, mako_config);
+		return new NACT_Sys2(crc32_a, crc32_b, config);
 	default:
-		return new NACT_Sys3(crc32_a, crc32_b, font_file, mako_config);
+		return new NACT_Sys3(crc32_a, crc32_b, config);
 	}
 }
diff --git a/src/sys/nact.h b/src/sys/nact.h
index c046763..1c1fd3f 100644
--- a/src/sys/nact.h
+++ b/src/sys/nact.h
@@ -7,6 +7,7 @@
 #ifndef _NACT_H_
 #define _NACT_H_
 
+#include <string>
 #include <stdio.h>
 #include "../common.h"
 #include "localization.h"
@@ -81,13 +82,13 @@
 class AGS;
 class MAKO;
 class MsgSkip;
-struct MAKOConfig;
+struct Config;
 
 class NACT
 {
 public:
-	static NACT* create(const char* game_id, const char* font_file, const MAKOConfig& mako_config);
-	NACT(int sys_ver, uint32 crc32_a, uint32 crc32_b, const char* font_file, const MAKOConfig& mako_config);
+	static NACT* create(const Config& config);
+	NACT(int sys_ver, uint32 crc32_a, uint32 crc32_b, const Config& config);
 	virtual ~NACT();
 
 protected:
@@ -228,7 +229,7 @@ protected:
 #endif
 	int mouse_x = 0, mouse_y = 0;
 
-	static uint32 calc_crc32(const char* file_name, const char* game_id);
+	static uint32 calc_crc32(const char* file_name, const std::string& game_id);
 
 	// Y27 ダイアログ
 	void text_dialog();
@@ -279,7 +280,7 @@ private:
 
 class NACT_Sys1 final : public NACT {
 public:
-	NACT_Sys1(uint32 crc32_a, uint32 crc32_b, const char* font_file, const MAKOConfig& mako_config);
+	NACT_Sys1(uint32 crc32_a, uint32 crc32_b, const Config& config);
 protected:
 	void cmd_calc() override;
 	void cmd_branch() override;
@@ -330,7 +331,7 @@ private:
 
 class NACT_Sys2 final : public NACT {
 public:
-	NACT_Sys2(uint32 crc32_a, uint32 crc32_b, const char* font_file, const MAKOConfig& mako_config);
+	NACT_Sys2(uint32 crc32_a, uint32 crc32_b, const Config& config);
 protected:
 	void cmd_calc() override;
 	void cmd_branch() override;
@@ -375,7 +376,7 @@ protected:
 
 class NACT_Sys3 final : public NACT {
 public:
-	NACT_Sys3(uint32 crc32_a, uint32 crc32_b, const char* font_file, const MAKOConfig& mako_config);
+	NACT_Sys3(uint32 crc32_a, uint32 crc32_b, const Config& config);
 protected:
 	void cmd_calc() override;
 	void cmd_branch() override;
@@ -418,6 +419,4 @@ protected:
 	uint16 cali2() override;
 };
 
-extern "C" void ags_setAntialiasedStringMode(int on);
-
 #endif // _NACT_H_
diff --git a/src/sys/nact_crc32.cpp b/src/sys/nact_crc32.cpp
index 8bc540a..121a630 100644
--- a/src/sys/nact_crc32.cpp
+++ b/src/sys/nact_crc32.cpp
@@ -90,11 +90,11 @@ const CRCTable* lookup(uint32 crc32_a, uint32 crc32_b)
 
 } // namespace
 
-uint32 NACT::calc_crc32(const char* file_name, const char* game_id)
+uint32 NACT::calc_crc32(const char* file_name, const std::string& game_id)
 {
-	if (game_id) {
+	if (!game_id.empty()) {
 		for (const CRCTable* t = crc_table; t->id; t++) {
-			if (strcmp(t->id, game_id) == 0)
+			if (t->id == game_id)
 				return file_name[0] == 'A' ? t->crc32_a : t->crc32_b;
 		}
 	}
diff --git a/src/sys/nact_sys1.cpp b/src/sys/nact_sys1.cpp
index 3708e44..a8e9f02 100644
--- a/src/sys/nact_sys1.cpp
+++ b/src/sys/nact_sys1.cpp
@@ -65,8 +65,8 @@
 	} \
 }
 
-NACT_Sys1::NACT_Sys1(uint32 crc32_a, uint32 crc32_b, const char* font_file, const MAKOConfig& mako_config)
-	: NACT(1, crc32_a, crc32_b, font_file, mako_config)
+NACT_Sys1::NACT_Sys1(uint32 crc32_a, uint32 crc32_b, const Config& config)
+	: NACT(1, crc32_a, crc32_b, config)
 {
 	switch (crc32_a) {
 	case CRC32_DPS:
diff --git a/src/sys/nact_sys2.cpp b/src/sys/nact_sys2.cpp
index ae41e63..4bbae44 100644
--- a/src/sys/nact_sys2.cpp
+++ b/src/sys/nact_sys2.cpp
@@ -57,8 +57,8 @@
 	} \
 }
 
-NACT_Sys2::NACT_Sys2(uint32 crc32_a, uint32 crc32_b, const char* font_file, const MAKOConfig& mako_config)
-	: NACT(2, crc32_a, crc32_b, font_file, mako_config)
+NACT_Sys2::NACT_Sys2(uint32 crc32_a, uint32 crc32_b, const Config& config)
+	: NACT(2, crc32_a, crc32_b, config)
 {
 }
 
diff --git a/src/sys/nact_sys3.cpp b/src/sys/nact_sys3.cpp
index ef2815d..e0cdedf 100644
--- a/src/sys/nact_sys3.cpp
+++ b/src/sys/nact_sys3.cpp
@@ -14,8 +14,8 @@
 #include "../fileio.h"
 #include "texthook.h"
 
-NACT_Sys3::NACT_Sys3(uint32 crc32_a, uint32 crc32_b, const char* font_file, const MAKOConfig& mako_config)
-	: NACT(3, crc32_a, crc32_b, font_file, mako_config)
+NACT_Sys3::NACT_Sys3(uint32 crc32_a, uint32 crc32_b, const Config& config)
+	: NACT(3, crc32_a, crc32_b, config)
 {
 }
 
diff --git a/src/win/mako.cpp b/src/win/mako.cpp
index 6494450..7dab20f 100644
--- a/src/win/mako.cpp
+++ b/src/win/mako.cpp
@@ -13,6 +13,7 @@
 #include "mako.h"
 #include "mako_midi.h"
 #include "fm/mako_fmgen.h"
+#include "../config.h"
 #include "dri.h"
 #include "crc32.h"
 
@@ -241,14 +242,14 @@ void audio_callback(void*, Uint8* stream, int len) {
 
 } // namespace
 
-MAKO::MAKO(NACT* parent, const MAKOConfig& config) :
+MAKO::MAKO(NACT* parent, const Config& config) :
 	use_fm(config.use_fm),
 	current_music(0),
 	next_loop(0),
 	nact(parent)
 {
-	if (config.playlist)
-		load_playlist(config.playlist);
+	if (!config.playlist.empty())
+		load_playlist(config.playlist.c_str());
 
 	strcpy_s(amus, 16, "AMUS.DAT");
 	strcpy_s(amse, 16, "AMSE.DAT");	// 実際には使わない