diff --git a/modules/NIGHTDLL/nt_msg.c b/modules/NIGHTDLL/nt_msg.c
index 9209789..aeec152 100644
--- a/modules/NIGHTDLL/nt_msg.c
+++ b/modules/NIGHTDLL/nt_msg.c
@@ -104,7 +104,7 @@ void ntmsg_init() {
 
 
 	// 主人公名前
-	nt_sstr_regist_replace(utf2sjis(SNAME_RYO), utf2sjis(SNAME_RYO_DEF));
+	nt_sstr_regist_replace(fromUTF8(SNAME_RYO), fromUTF8(SNAME_RYO_DEF));
 	
 	night.msg.cbmove = cb_mousemove;
 	night.msg.cbrelease = cb_keyrelease;
diff --git a/modules/SACT/sactlog.c b/modules/SACT/sactlog.c
index f2dfec1..4372234 100644
--- a/modules/SACT/sactlog.c
+++ b/modules/SACT/sactlog.c
@@ -43,7 +43,7 @@
 
 #define LOGMSG_LINES 6
 
-static const char *logmsg[LOGMSG_LINES] = {
+static const char *logmsg_utf8[LOGMSG_LINES] = {
 	"\n",
 	"※バックログ操作方法※",
 	"[ESC]またはマウス右クリックでゲームに戻る",
@@ -110,15 +110,15 @@ static void draw_log() {
 
 
 int sblog_start(void) {
-	static char *logmsg_sjis[6];
-	if (!logmsg_sjis[0]) {
+	static char *logmsg[LOGMSG_LINES];
+	if (!logmsg[0]) {
 		for (int i = 0; i < LOGMSG_LINES; i++)
-			logmsg_sjis[i] = utf2sjis(logmsg[i]);
+			logmsg[i] = fromUTF8(logmsg_utf8[i]);
 	}
 
 	// 説明文章を追加
 	for (int i = 0; i < LOGMSG_LINES; i++)
-		sact.log = list_append(sact.log, logmsg_sjis[i]);
+		sact.log = list_append(sact.log, logmsg[i]);
 	
 	back = sf_dup(sf0);
 	chr  = sf_create_surface(sf0->width, sf0->height, 8);
diff --git a/src/ags.c b/src/ags.c
index 144f9fa..cb25442 100644
--- a/src/ags.c
+++ b/src/ags.c
@@ -186,16 +186,16 @@ void ags_setViewArea(int x, int y, int width, int height) {
 
 void ags_setWindowTitle(const char *src) {
 #define TITLEHEAD "XSystem35 Version "VERSION":"
-	BYTE *dst, *d;
+	BYTE *utf, *d;
 
-	dst = sjis2utf(src);
-	if (NULL == (d = malloc(strlen(dst) + strlen(TITLEHEAD) + 1))) {
+	utf = toUTF8(src);
+	if (NULL == (d = malloc(strlen(utf) + strlen(TITLEHEAD) + 1))) {
 		NOMEMERR();
 	}
 	strcpy(d, TITLEHEAD);
-	strcat(d, dst);
+	strcat(d, utf);
 	SetWindowTitle(d);
-	free(dst);
+	free(utf);
 	free(d);
 }
 
@@ -402,7 +402,7 @@ int ags_drawString(int x, int y, const char *src, int col) {
 	if (!check_param_xy(&x, &y)) return 0;
 	
 	DspDeviceSync();
-	char *utf8 = sjis2utf(src);
+	char *utf8 = toUTF8(src);
 	w = DrawString(x, y, utf8, col);
 	free(utf8);
 
@@ -410,7 +410,7 @@ int ags_drawString(int x, int y, const char *src, int col) {
 }
 
 agsurface_t *ags_drawStringToSurface(const char *str) {
-	char *utf8 = sjis2utf(str);
+	char *utf8 = toUTF8(str);
 	agsurface_t *sf = nact->ags.font->get_glyph(utf8);
 	free(utf8);
 	return sf;
diff --git a/src/cmd2F.c b/src/cmd2F.c
index e33ede4..579af93 100644
--- a/src/cmd2F.c
+++ b/src/cmd2F.c
@@ -367,7 +367,7 @@ void commands2F23() {
 	int y = getCaliValue();
 	char *vFileName = sys_getString(0);
 	
-	char *fname_utf8 = sjis2utf(vFileName);
+	char *fname_utf8 = toUTF8(vFileName);
 	sysVar[0] = cg_load_with_filename(fname_utf8, x, y);
 	free(fname_utf8);
 	
@@ -380,7 +380,7 @@ void commands2F24() {
 	int *var = NULL, _var = 0;
 	int num = 0;
 
-	char *fname_utf8 = sjis2utf(file_name);
+	char *fname_utf8 = toUTF8(file_name);
 	switch(type) {
 	case 0:
 		var = getCaliVariable();
@@ -412,8 +412,8 @@ void commands2F26() {
 	char *title  = sys_getString(0);
 	char *t1, *t2, *t3;
 	
-	t1 = sjis2utf(title);
-	t2 = sjis2utf(v_str(dst_no -1));
+	t1 = toUTF8(title);
+	t2 = toUTF8(v_str(dst_no -1));
 	
 	mi_param.title = t1;
 	mi_param.oldstring = t2;
@@ -426,10 +426,10 @@ void commands2F26() {
 		return;
 	}
 	
-	t3 = utf2sjis(mi_param.newstring);
+	t3 = fromUTF8(mi_param.newstring);
 	
 	/* 全角文字以外は不可 */
-	if (!sjis_has_hankaku(t3)) {
+	if (nact->encoding != SHIFT_JIS || !sjis_has_hankaku(t3)) {
 		v_strcpy(dst_no -1, t3);
 	}
 	free(t1);
@@ -457,7 +457,7 @@ void commands2F28() {
 	
 	if (nact->game_title_utf8)
 		free(nact->game_title_utf8);
-	nact->game_title_utf8 = sjis2utf(title);
+	nact->game_title_utf8 = toUTF8(title);
 
 	ags_setWindowTitle(title);
 
@@ -478,7 +478,7 @@ void commands2F29() {
 	if (ni_param.title != NULL) {
 		free(ni_param.title);
 	}
-	t = sjis2utf(title);
+	t = toUTF8(title);
 	ni_param.title = t;
 	
 	DEBUG_COMMAND("NT(new) %s:\n", title);
@@ -489,7 +489,7 @@ void commands2F2A() {
 	char *file_name = sys_getString(0);
 	int *var, _var = 0, cnt;
 
-	char *fname_utf8 = sjis2utf(file_name);
+	char *fname_utf8 = toUTF8(file_name);
 	switch(type) {
 	case 0:
 		var = getCaliVariable();
@@ -924,8 +924,8 @@ void commands2F57() {
 	char *t1, *t2, *t3;
 	INPUTSTRING_PARAM p;
 	
-	t1 = sjis2utf(sTitle);
-	t2 = sjis2utf(v_str(eStrVar -1));
+	t1 = toUTF8(sTitle);
+	t2 = toUTF8(v_str(eStrVar -1));
 	p.title = t1;
 	p.oldstring = t2;
 	p.max = eLength;
@@ -934,10 +934,10 @@ void commands2F57() {
 	if (p.newstring == NULL) {
 		*vResult = 65535;
 	} else {
-		t3 = utf2sjis(p.newstring);
-		if (!sjis_has_hankaku(t3)) {
+		t3 = fromUTF8(p.newstring);
+		if (nact->encoding != SHIFT_JIS || !sjis_has_hankaku(t3)) {
 			v_strcpy(eStrVar -1, t3);
-			*vResult = sjis_count_char(t3);
+			*vResult = v_strlen(eStrVar -1);
 		} else {
 			*vResult = 65535;
 		}
@@ -971,7 +971,7 @@ void commands2F5A() {
 	char *sText = sys_getString(0);
 	char *t1;
 	
-	t1 = sjis2utf(sText);
+	t1 = toUTF8(sText);
 	menu_msgbox_open(t1);
 	free(t1);
 	
@@ -982,7 +982,7 @@ void commands2F5B() {
 	int eNum = getCaliValue();
 	char *t1;
 	
-	t1 = sjis2utf(v_str(eNum) - 1);
+	t1 = toUTF8(v_str(eNum) - 1);
 	menu_msgbox_open(t1);
 	free(t1);
 	
diff --git a/src/cmd_check.c b/src/cmd_check.c
index 3e7df3c..38a3448 100644
--- a/src/cmd_check.c
+++ b/src/cmd_check.c
@@ -1098,6 +1098,8 @@ void check_command(int c0) {
 				undeferr();
 			}
 			 break;
+		case 'U':
+			commandZU(); break;
 		case 'Z':
 			switch(sl_getc()) {
 			case 0:
diff --git a/src/cmd_check.h b/src/cmd_check.h
index 4a1c5d6..04c3cb7 100644
--- a/src/cmd_check.h
+++ b/src/cmd_check.h
@@ -304,6 +304,7 @@ extern void commandZI();
 extern void commandZA();
 extern void commandZK();
 extern void commandZR();
+extern void commandZU();
 
 /* define in cmd2F.c */
 extern void commands2F00();
diff --git a/src/cmdh.c b/src/cmdh.c
index e4aac78..faf0910 100644
--- a/src/cmdh.c
+++ b/src/cmdh.c
@@ -22,9 +22,11 @@
 /* $Id: cmdh.c,v 1.5 2000/09/10 10:39:48 chikama Exp $ */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include "portab.h"
 #include "xsystem35.h"
+#include "utfsjis.h"
 #include "hankaku.h"
 
 void commandH() {
@@ -32,7 +34,9 @@ void commandH() {
 	int num = getCaliValue();
 	char buf[512];
 
-	sys_addMsg(format_number_zenkaku(num, fig, buf));
+	char *s = fromSJIS(format_number_zenkaku(num, fig, buf));
+	sys_addMsg(s);
+	free(s);
 
 	DEBUG_COMMAND("H %d,%d:\n",fig,num);
 }
diff --git a/src/cmdl.c b/src/cmdl.c
index a218868..11c0bf5 100644
--- a/src/cmdl.c
+++ b/src/cmdl.c
@@ -112,7 +112,7 @@ void commandLE() {
 	int *var, _var = 0;
 	int num;
 
-	char *fname_utf8 = sjis2utf(filename);
+	char *fname_utf8 = toUTF8(filename);
 	switch(type) {
 	case 0: /* T2 */
 		var = getCaliVariable();
@@ -246,7 +246,7 @@ void commandLC() {
 	int y = getCaliValue();
 	char *filename = sys_getString(':'); 
 	
-	char *fname_utf8 = sjis2utf(filename);
+	char *fname_utf8 = toUTF8(filename);
 	sysVar[0] = cg_load_with_filename(fname_utf8, x, y);
 	free(fname_utf8);
 	
diff --git a/src/cmdm.c b/src/cmdm.c
index e45d630..b5d6efb 100644
--- a/src/cmdm.c
+++ b/src/cmdm.c
@@ -62,34 +62,37 @@ void commandMP() {
 	/* 指定の文字列を指定文字数だけ表示する（Ｘコマンドの桁数指定） */
 	int    num1 = getCaliValue();
 	int    num2 = getCaliValue();
-	const char bstr[3] = "\x81\x40"; // full-width whitespace
+	const char *fullwidth_blank[CHARACTER_ENCODING_MAX + 1] = {
+		[SHIFT_JIS] = "\x81\x40",
+		[UTF8] = "　",
+	};
 	const char *src = v_str(num1 - 1);
 	int chars = num2;
 	char *str;
 
 	/* Patched English executable appends num2 spaces instead of truncating */
 	if (have_eng_mp_patch) {
-		str = calloc(strlen(src) + num2 * 2 + 1, 1);
+		str = calloc(strlen(src) + num2 * strlen(fullwidth_blank[nact->encoding]) + 1, 1);
 		if (NULL == str) {
 			NOMEMERR();
 		}
 		strcpy(str, src);
 	}
 	else {
-		str = calloc(num2 * 2 + 1, 1);
+		str = calloc(num2 * MAX_BYTES_PAR_CHAR(nact->encoding) + 1, 1);
 		if (NULL == str) {
 			NOMEMERR();
 		}
 
 		const char *p = src;
 		while (*p && chars > 0) {
-			p += CHECKSJIS1BYTE(*p) ? 2 : 1;
+			p = advance_char(p, nact->encoding);
 			chars--;
 		}
 		strncpy(str, src, p - src);
 	}
 	while (chars-- > 0) {
-		strcat(str, bstr);
+		strcat(str, fullwidth_blank[nact->encoding]);
 	}
 
 	sys_addMsg(str);
@@ -105,8 +108,8 @@ void commandMI() { /* T2 */
 	char *title = sys_getString(':');
 	char *t1, *t2, *t3;
 	
-	t1 = sjis2utf(title);
-	t2 = sjis2utf(v_str(dst_no -1));
+	t1 = toUTF8(title);
+	t2 = toUTF8(v_str(dst_no -1));
 	
 	mi_param.title = t1;
 	mi_param.oldstring = t2;
@@ -119,10 +122,10 @@ void commandMI() { /* T2 */
 		return;
 	}
 	
-	t3 = utf2sjis(mi_param.newstring);
+	t3 = fromUTF8(mi_param.newstring);
 	
 	/* 全角文字以外は不可 */
-	if (!sjis_has_hankaku(t3)) {
+	if (nact->encoding != SHIFT_JIS ||!sjis_has_hankaku(t3)) {
 		v_strcpy(dst_no -1, t3);
 	}
 	free(t1);
@@ -163,7 +166,7 @@ void commandMT() {
 	
 	if (nact->game_title_utf8)
 		free(nact->game_title_utf8);
-	nact->game_title_utf8 = sjis2utf(str);
+	nact->game_title_utf8 = toUTF8(str);
 	ags_setWindowTitle(str);
 	
 	/* 闘神都市II 対策 */
@@ -197,7 +200,9 @@ void commandMH() {
 	int num2 = getCaliValue();
 
 	char buf[512];
-	v_strcpy(num1 - 1, format_number_zenkaku(num2, fig, buf));
+	char *s = fromSJIS(format_number_zenkaku(num2, fig, buf));
+	v_strcpy(num1 - 1, s);
+	free(s);
 
 	DEBUG_COMMAND("MH %d,%d,%d:\n",num1,fig,num2);
 }
@@ -215,7 +220,7 @@ void commandML() {
 	int *var   = getCaliVariable();
 	int str_no = getCaliValue();
 	
-	*var = sjis_count_char(v_str(str_no -1));
+	*var = v_strlen(str_no -1);
 	
 	DEBUG_COMMAND("ML %p,%d:\n",var, str_no);
 }
@@ -338,7 +343,7 @@ void commandMJ() {
 	INPUTSTRING_PARAM mj_param;
 	char *t1, *t2;
 	
-	t1 = sjis2utf(v_str(num -1));
+	t1 = toUTF8(v_str(num -1));
 	mj_param.max = max_len;
 	mj_param.x = x;
 	mj_param.y = y;
@@ -349,8 +354,8 @@ void commandMJ() {
 	menu_inputstring2(&mj_param);
 	if (mj_param.newstring == NULL) return;
 	
-	t2 = utf2sjis(mj_param.newstring);
-	if (!sjis_has_hankaku(t2)) {
+	t2 = fromUTF8(mj_param.newstring);
+	if (nact->encoding != SHIFT_JIS || !sjis_has_hankaku(t2)) {
 		v_strcpy(num -1, t2);
 	}
 	free(t1);
diff --git a/src/cmdn.c b/src/cmdn.c
index 6abff7d..59d35b7 100644
--- a/src/cmdn.c
+++ b/src/cmdn.c
@@ -375,13 +375,9 @@ void commandNI() { /* From Panyo */
 void commandNT() { /* From Panyo */
 	/* NIコマンドで表示するタイトルを設定する。*/
 	char *str = sys_getString(':');
-	char *t;
 
-	if (ni_param.title != NULL) {
-		free(ni_param.title);
-	}
-	t = sjis2utf(str);
-	ni_param.title = t;
+	free(ni_param.title);
+	ni_param.title = toUTF8(str);
 	
 	DEBUG_COMMAND("NT %p:\n", str);
 }
diff --git a/src/cmdq.c b/src/cmdq.c
index aaa30e6..587396a 100644
--- a/src/cmdq.c
+++ b/src/cmdq.c
@@ -87,7 +87,7 @@ void commandQE() {
 	char *filename = sys_getString(':');
 	int *var, _var = 0, cnt;
 
-	char *fname_utf8 = sjis2utf(filename);
+	char *fname_utf8 = toUTF8(filename);
 	switch(type) {
 	case 0:
 		var = getCaliVariable();
diff --git a/src/cmdz.c b/src/cmdz.c
index 697af2e..d2f0ad4 100644
--- a/src/cmdz.c
+++ b/src/cmdz.c
@@ -525,3 +525,13 @@ void commandZR() {
 	
 	DEBUG_COMMAND("ZR %d,%d:\n", num, *var);
 }
+
+void commandZU() {
+	/* xsystem35 extension: sets unicode mode */
+	int sw = getCaliValue();
+
+	if (sw <= CHARACTER_ENCODING_MAX)
+		sys_setCharacterEncoding(sw);
+
+	DEBUG_COMMAND("ZU %d:\n",sw);
+}
diff --git a/src/font_freetype2.c b/src/font_freetype2.c
index 39f30a5..8dd43cf 100644
--- a/src/font_freetype2.c
+++ b/src/font_freetype2.c
@@ -34,6 +34,7 @@
 #include "system.h"
 #include "font.h"
 #include "ags.h"
+#include "utfsjis.h"
 
 extern const unsigned short *s2u[];
 
@@ -59,35 +60,6 @@ static FONT *this;
 static void pixmap2comimg(BYTE *src, int x, int y, int w, int h, int src_bpl);
 static void pixmapmono2comimg(BYTE *src, int x, int y, int w, int h, int src_bpl);
 
-static int utf8_next_codepoint(const char **msg) {
-	int code;
-	const unsigned char *s = (const unsigned char *)*msg;
-
-	if (*s <= 0x7f) {
-		code = *s++;
-	} else if (*s <= 0xbf) {
-		WARNING("Invalid UTF-8 sequence %02x\n", *s);
-		code = '?';
-		s++;
-	} else if (*s <= 0xdf) {
-		code = (s[0] & 0x1f) << 6 | (s[1] & 0x3f);
-		s += 2;
-	} else if (*s <= 0xef) {
-		code = (s[0] & 0xf) << 12 | (s[1] & 0x3f) << 6 | (s[2] & 0x3f);
-		s += 3;
-	} else if (*s <= 0xf7) {
-		code = (s[0] & 0x7) << 18 | (s[1] & 0x3f) << 12 | (s[2] & 0x3f) << 6 | (s[3] & 0x3f);
-		s += 4;
-	} else {
-		code = 0xfffd;  // REPLACEMENT CHARACTER
-		s++;
-		while (0x80 <= *s && *s <= 0xbf)
-			s++;
-	}
-	*msg = (const char *)s;
-	return code;
-}
-
 static boolean select_charmap(FT_Face f, int type) {
 	int i;
 	
diff --git a/src/hankaku.c b/src/hankaku.c
index 6ea5b23..87a2e53 100644
--- a/src/hankaku.c
+++ b/src/hankaku.c
@@ -140,7 +140,7 @@ static const char zenkaku_digits[][3] = {
 	0x81,0x40,0x00, /* space */
 };
 
-BYTE *zen2han(const BYTE *src) {
+static BYTE *zen2han_sjis(const BYTE *src) {
 	BYTE c0, c1;
 	char *dst, *_dst;
 	
@@ -173,7 +173,201 @@ BYTE *zen2han(const BYTE *src) {
 	return _dst;
 }
 
-BYTE *han2zen(const BYTE *src) {
+static char *zen2han_utf8(const char *src) {
+	char *dst, *_dst;
+	dst = _dst = malloc(strlen(src) + 1);
+	if (dst == NULL) {
+		fprintf(stderr, "zen2han(): Out of Memory (size %zu)", strlen(src) + 1);
+		return NULL;
+	}
+
+	const char *p = src;
+	while (*p) {
+		const char *prev = p;
+		switch (utf8_next_codepoint(&p)) {
+		case L'’': *dst++ = '\''; break;
+		case L'”': *dst++ = '"'; break;
+		case L'　': *dst++ = ' '; break;
+		case L'、': strcpy(dst, "､"); dst += 3; break;
+		case L'。': strcpy(dst, "｡"); dst += 3; break;
+		case L'「': strcpy(dst, "｢"); dst += 3; break;
+		case L'」': strcpy(dst, "｣"); dst += 3; break;
+		case L'゛': strcpy(dst, "ﾞ"); dst += 3; break;
+		case L'゜': strcpy(dst, "ﾟ"); dst += 3; break;
+		case L'ァ': strcpy(dst, "ｧ"); dst += 3; break;
+		case L'ア': strcpy(dst, "ｱ"); dst += 3; break;
+		case L'ィ': strcpy(dst, "ｨ"); dst += 3; break;
+		case L'イ': strcpy(dst, "ｲ"); dst += 3; break;
+		case L'ゥ': strcpy(dst, "ｩ"); dst += 3; break;
+		case L'ウ': strcpy(dst, "ｳ"); dst += 3; break;
+		case L'ェ': strcpy(dst, "ｪ"); dst += 3; break;
+		case L'エ': strcpy(dst, "ｴ"); dst += 3; break;
+		case L'ォ': strcpy(dst, "ｫ"); dst += 3; break;
+		case L'オ': strcpy(dst, "ｵ"); dst += 3; break;
+		case L'カ': strcpy(dst, "ｶ"); dst += 3; break;
+		case L'キ': strcpy(dst, "ｷ"); dst += 3; break;
+		case L'ク': strcpy(dst, "ｸ"); dst += 3; break;
+		case L'ケ': strcpy(dst, "ｹ"); dst += 3; break;
+		case L'コ': strcpy(dst, "ｺ"); dst += 3; break;
+		case L'サ': strcpy(dst, "ｻ"); dst += 3; break;
+		case L'シ': strcpy(dst, "ｼ"); dst += 3; break;
+		case L'ス': strcpy(dst, "ｽ"); dst += 3; break;
+		case L'セ': strcpy(dst, "ｾ"); dst += 3; break;
+		case L'ソ': strcpy(dst, "ｿ"); dst += 3; break;
+		case L'タ': strcpy(dst, "ﾀ"); dst += 3; break;
+		case L'チ': strcpy(dst, "ﾁ"); dst += 3; break;
+		case L'ッ': strcpy(dst, "ｯ"); dst += 3; break;
+		case L'ツ': strcpy(dst, "ﾂ"); dst += 3; break;
+		case L'テ': strcpy(dst, "ﾃ"); dst += 3; break;
+		case L'ト': strcpy(dst, "ﾄ"); dst += 3; break;
+		case L'ナ': strcpy(dst, "ﾅ"); dst += 3; break;
+		case L'ニ': strcpy(dst, "ﾆ"); dst += 3; break;
+		case L'ヌ': strcpy(dst, "ﾇ"); dst += 3; break;
+		case L'ネ': strcpy(dst, "ﾈ"); dst += 3; break;
+		case L'ノ': strcpy(dst, "ﾉ"); dst += 3; break;
+		case L'ハ': strcpy(dst, "ﾊ"); dst += 3; break;
+		case L'ヒ': strcpy(dst, "ﾋ"); dst += 3; break;
+		case L'フ': strcpy(dst, "ﾌ"); dst += 3; break;
+		case L'ヘ': strcpy(dst, "ﾍ"); dst += 3; break;
+		case L'ホ': strcpy(dst, "ﾎ"); dst += 3; break;
+		case L'マ': strcpy(dst, "ﾏ"); dst += 3; break;
+		case L'ミ': strcpy(dst, "ﾐ"); dst += 3; break;
+		case L'ム': strcpy(dst, "ﾑ"); dst += 3; break;
+		case L'メ': strcpy(dst, "ﾒ"); dst += 3; break;
+		case L'モ': strcpy(dst, "ﾓ"); dst += 3; break;
+		case L'ャ': strcpy(dst, "ｬ"); dst += 3; break;
+		case L'ヤ': strcpy(dst, "ﾔ"); dst += 3; break;
+		case L'ュ': strcpy(dst, "ｭ"); dst += 3; break;
+		case L'ユ': strcpy(dst, "ﾕ"); dst += 3; break;
+		case L'ョ': strcpy(dst, "ｮ"); dst += 3; break;
+		case L'ヨ': strcpy(dst, "ﾖ"); dst += 3; break;
+		case L'ラ': strcpy(dst, "ﾗ"); dst += 3; break;
+		case L'リ': strcpy(dst, "ﾘ"); dst += 3; break;
+		case L'ル': strcpy(dst, "ﾙ"); dst += 3; break;
+		case L'レ': strcpy(dst, "ﾚ"); dst += 3; break;
+		case L'ロ': strcpy(dst, "ﾛ"); dst += 3; break;
+		case L'ワ': strcpy(dst, "ﾜ"); dst += 3; break;
+		case L'ヲ': strcpy(dst, "ｦ"); dst += 3; break;
+		case L'ン': strcpy(dst, "ﾝ"); dst += 3; break;
+		case L'・': strcpy(dst, "･"); dst += 3; break;
+		case L'ー': strcpy(dst, "ｰ"); dst += 3; break;
+		case L'！': *dst++ = '!'; break;
+		case L'＃': *dst++ = '#'; break;
+		case L'＄': *dst++ = '$'; break;
+		case L'％': *dst++ = '%'; break;
+		case L'＆': *dst++ = '&'; break;
+		case L'（': *dst++ = '('; break;
+		case L'）': *dst++ = ')'; break;
+		case L'＊': *dst++ = '*'; break;
+		case L'＋': *dst++ = '+'; break;
+		case L'，': *dst++ = ','; break;
+		case L'－': *dst++ = '-'; break;
+		case L'．': *dst++ = '.'; break;
+		case L'／': *dst++ = '/'; break;
+		case L'０': *dst++ = '0'; break;
+		case L'１': *dst++ = '1'; break;
+		case L'２': *dst++ = '2'; break;
+		case L'３': *dst++ = '3'; break;
+		case L'４': *dst++ = '4'; break;
+		case L'５': *dst++ = '5'; break;
+		case L'６': *dst++ = '6'; break;
+		case L'７': *dst++ = '7'; break;
+		case L'８': *dst++ = '8'; break;
+		case L'９': *dst++ = '9'; break;
+		case L'：': *dst++ = ':'; break;
+		case L'；': *dst++ = ';'; break;
+		case L'＜': *dst++ = '<'; break;
+		case L'＝': *dst++ = '='; break;
+		case L'＞': *dst++ = '>'; break;
+		case L'？': *dst++ = '?'; break;
+		case L'＠': *dst++ = '@'; break;
+		case L'Ａ': *dst++ = 'A'; break;
+		case L'Ｂ': *dst++ = 'B'; break;
+		case L'Ｃ': *dst++ = 'C'; break;
+		case L'Ｄ': *dst++ = 'D'; break;
+		case L'Ｅ': *dst++ = 'E'; break;
+		case L'Ｆ': *dst++ = 'F'; break;
+		case L'Ｇ': *dst++ = 'G'; break;
+		case L'Ｈ': *dst++ = 'H'; break;
+		case L'Ｉ': *dst++ = 'I'; break;
+		case L'Ｊ': *dst++ = 'J'; break;
+		case L'Ｋ': *dst++ = 'K'; break;
+		case L'Ｌ': *dst++ = 'L'; break;
+		case L'Ｍ': *dst++ = 'M'; break;
+		case L'Ｎ': *dst++ = 'N'; break;
+		case L'Ｏ': *dst++ = 'O'; break;
+		case L'Ｐ': *dst++ = 'P'; break;
+		case L'Ｑ': *dst++ = 'Q'; break;
+		case L'Ｒ': *dst++ = 'R'; break;
+		case L'Ｓ': *dst++ = 'S'; break;
+		case L'Ｔ': *dst++ = 'T'; break;
+		case L'Ｕ': *dst++ = 'U'; break;
+		case L'Ｖ': *dst++ = 'V'; break;
+		case L'Ｗ': *dst++ = 'W'; break;
+		case L'Ｘ': *dst++ = 'X'; break;
+		case L'Ｙ': *dst++ = 'Y'; break;
+		case L'Ｚ': *dst++ = 'Z'; break;
+		case L'［': *dst++ = '['; break;
+		case L'］': *dst++ = ']'; break;
+		case L'＾': *dst++ = '^'; break;
+		case L'＿': *dst++ = '_'; break;
+		case L'｀': *dst++ = '`'; break;
+		case L'ａ': *dst++ = 'a'; break;
+		case L'ｂ': *dst++ = 'b'; break;
+		case L'ｃ': *dst++ = 'c'; break;
+		case L'ｄ': *dst++ = 'd'; break;
+		case L'ｅ': *dst++ = 'e'; break;
+		case L'ｆ': *dst++ = 'f'; break;
+		case L'ｇ': *dst++ = 'g'; break;
+		case L'ｈ': *dst++ = 'h'; break;
+		case L'ｉ': *dst++ = 'i'; break;
+		case L'ｊ': *dst++ = 'j'; break;
+		case L'ｋ': *dst++ = 'k'; break;
+		case L'ｌ': *dst++ = 'l'; break;
+		case L'ｍ': *dst++ = 'm'; break;
+		case L'ｎ': *dst++ = 'n'; break;
+		case L'ｏ': *dst++ = 'o'; break;
+		case L'ｐ': *dst++ = 'p'; break;
+		case L'ｑ': *dst++ = 'q'; break;
+		case L'ｒ': *dst++ = 'r'; break;
+		case L'ｓ': *dst++ = 's'; break;
+		case L'ｔ': *dst++ = 't'; break;
+		case L'ｕ': *dst++ = 'u'; break;
+		case L'ｖ': *dst++ = 'v'; break;
+		case L'ｗ': *dst++ = 'w'; break;
+		case L'ｘ': *dst++ = 'x'; break;
+		case L'ｙ': *dst++ = 'y'; break;
+		case L'ｚ': *dst++ = 'z'; break;
+		case L'｛': *dst++ = '{'; break;
+		case L'｜': *dst++ = '|'; break;
+		case L'｝': *dst++ = '}'; break;
+		case L'￣': *dst++ = '~'; break;
+		case L'￥': *dst++ = '\\'; break;
+		default:
+			while (prev < p)
+				*dst++ = *prev++;
+			break;
+		}
+	}
+	*dst = 0;
+	return _dst;
+}
+
+BYTE *zen2han(const BYTE *src, CharacterEncoding enc) {
+	switch (enc) {
+	case SHIFT_JIS:
+		return zen2han_sjis(src);
+	case UTF8:
+		return zen2han_utf8(src);
+	default:
+		return (BYTE *)src;
+	}
+}
+
+BYTE *han2zen(const BYTE *src, CharacterEncoding enc) {
+	if (enc != SHIFT_JIS)
+		return (BYTE *)src; // Not implemented
+
 	BYTE c0;
 	BYTE *dst, *_dst;
 	dst = _dst = malloc(strlen(src) * 2 + 1);
diff --git a/src/hankaku.h b/src/hankaku.h
index 5b92cda..9d74f79 100644
--- a/src/hankaku.h
+++ b/src/hankaku.h
@@ -24,9 +24,10 @@
 #define __HANKAKU_H__
 
 #include "portab.h"
+#include "utfsjis.h"
 
-extern BYTE *zen2han(const BYTE *src);
-extern BYTE *han2zen(const BYTE *src);
+extern BYTE *zen2han(const BYTE *src, CharacterEncoding enc);
+extern BYTE *han2zen(const BYTE *src, CharacterEncoding enc);
 extern char *format_number(int n, int width, char *buf);
 extern char *format_number_zenkaku(int n, int width, char *buf);
 
diff --git a/src/hankaku_test.c b/src/hankaku_test.c
index 9feef71..a528cfc 100644
--- a/src/hankaku_test.c
+++ b/src/hankaku_test.c
@@ -52,9 +52,11 @@ static void zen2han_test(void) {
 		"ベペボポヮヰヱヴヵヶΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΠΡΣΤΥΦΧΨΩα"
 		"βγδεζηθικλμνξοπρστυφχψω";
 	for (const Zen2hanTestCase *tc = testcases; tc->zen; tc++) {
-		ASSERT_STRCMP(sjis2utf(zen2han(utf2sjis(tc->zen))), tc->han);
+		ASSERT_STRCMP(sjis2utf(zen2han(utf2sjis(tc->zen), SHIFT_JIS)), tc->han);
+		ASSERT_STRCMP(zen2han(tc->zen, UTF8), tc->han);
 	}
-	ASSERT_STRCMP(sjis2utf(zen2han(utf2sjis(unconvertable))), unconvertable);
+	ASSERT_STRCMP(sjis2utf(zen2han(utf2sjis(unconvertable), SHIFT_JIS)), unconvertable);
+	ASSERT_STRCMP(zen2han(unconvertable, UTF8), unconvertable);
 }
 
 static void format_number_test(void) {
diff --git a/src/message.c b/src/message.c
index cd83fc2..4579b56 100644
--- a/src/message.c
+++ b/src/message.c
@@ -326,11 +326,14 @@ void msg_getMessageLocation(MyPoint *loc) {
 
 void msg_hitAnyKey() {
 	int w;
-	static BYTE hak[] = {0x81, 0xa5, 0x00}; /* ▼ */
+	const char *prompt[CHARACTER_ENCODING_MAX + 1] = {
+		[SHIFT_JIS] = "\x81\xa5",
+		[UTF8] = "▼",
+	};
 	
 	w = ags_drawString(msg.win->x + msg.win->width - msg.MsgFontSize,
 			   msg.win->y + msg.win->height - msg.MsgFontSize,
-			   hak, msg.HitAnyKeyMsgColor);
+			   prompt[nact->encoding], msg.HitAnyKeyMsgColor);
 	ags_updateArea(msg.win->x + msg.win->width  - msg.MsgFontSize,
 		       msg.win->y + msg.win->height - msg.MsgFontSize,
 		       w, msg.MsgFontSize);
diff --git a/src/nact.c b/src/nact.c
index be1743f..50da3fe 100644
--- a/src/nact.c
+++ b/src/nact.c
@@ -70,6 +70,10 @@ void sys_setHankakuMode(int mode) {
 	msg_msgHankakuMode = mode;
 }
 
+void sys_setCharacterEncoding(CharacterEncoding encoding) {
+	nact->encoding = encoding;
+}
+
 /* 文字列の取り出し */
 char *sys_getString(char term) {
 	int c0;
@@ -103,9 +107,9 @@ void sys_addMsg(const char *str) {
 
 	switch(msg_msgHankakuMode) {
 	case 0:
-		msg = han2zen(str); break;
+		msg = han2zen(str, nact->encoding); break;
 	case 1:
-		msg = zen2han(str); break;
+		msg = zen2han(str, nact->encoding); break;
 	case 2:
 		msg = str; break;
 	default:
@@ -126,7 +130,7 @@ void sys_addMsg(const char *str) {
 		}
 	}
 	
-	if (msg && msg_msgHankakuMode < 2) {
+	if (msg != str) {
 		free((char *)msg);
 	}
 }
@@ -136,8 +140,10 @@ static int checkMessage() {
 	char *index = msgbuf;
 	int c0 = sl_getc();
 	
-	while (c0 == 0x20 || c0 > 0x80) {
-		if (c0 == 0x20) {
+	while (c0 == 0x20 || c0 >= 0x80) {
+		if (nact->encoding == UTF8) {
+			*index++ = (char)c0;
+		} else if (c0 == 0x20) {
 			*index++ = (char)c0;
 		} else if (c0 >= 0xe0) {
 			*index++ = (char)c0; *index++ = (char)sl_getc();
diff --git a/src/nact.h b/src/nact.h
index 08bdece..77d37f9 100644
--- a/src/nact.h
+++ b/src/nact.h
@@ -32,6 +32,12 @@
 #include "selection.h"
 #include "message.h"
 #include "ags.h"
+#include "utfsjis.h"
+
+#define toUTF8(s)   codeconv(UTF8, nact->encoding, s)
+#define toSJIS(s)   codeconv(SHIFT_JIS, nact->encoding, s)
+#define fromUTF8(s) codeconv(nact->encoding, UTF8, s)
+#define fromSJIS(s) codeconv(nact->encoding, SHIFT_JIS, s)
 
 /* コマンド解析時に参照する */
 #define sys_getc            sl_getc
@@ -46,6 +52,7 @@ extern int *getVariable();
 extern char *sys_getString(char term);
 extern void sys_addMsg(const char *str);
 extern void sys_setHankakuMode(int mode);
+extern void sys_setCharacterEncoding(CharacterEncoding encoding);
 extern char *sys_getConstString();
 
 // extern boolean sys_nact_engine();
@@ -61,6 +68,7 @@ typedef struct {
 	boolean   is_message_locked;   /* pointer 等の event handler を呼び出さない */
 	boolean   popupmenu_opened;    /* popup menu が 開いているか */
 	boolean   mmx_is_ok;           /* MMX が有効かどうか */
+	CharacterEncoding encoding;
 	
 	char      *game_title_utf8;
 	int        scenario_version;
diff --git a/src/utfsjis.c b/src/utfsjis.c
index 1e1f5ee..8f0e52c 100644
--- a/src/utfsjis.c
+++ b/src/utfsjis.c
@@ -33,6 +33,18 @@
 #include "utfsjis.h"
 #include "s2utbl.h"
 
+char* codeconv(CharacterEncoding tocode,
+			   CharacterEncoding fromcode,
+			   const char *str) {
+	if (tocode == fromcode)
+		return strdup(str);
+	if (tocode == UTF8 && fromcode == SHIFT_JIS)
+		return (char *)sjis2utf((char *)str);
+	if (tocode == SHIFT_JIS && fromcode == UTF8)
+		return (char *)utf2sjis((char *)str);
+	return NULL;
+}
+
 BYTE *sjis2utf(const BYTE *src) {
 	BYTE* dst = malloc(strlen(src) * 3 + 1);
 	BYTE* dstp = dst;
@@ -147,15 +159,43 @@ boolean sjis_has_zenkaku(const BYTE *src) {
 	return FALSE;
 }
 
-/* src 中の文字数を数える 全角文字も１文字 */
-int sjis_count_char(const BYTE *src) {
-	int c = 0;
-	
-	while(*src) {
-		if (CHECKSJIS1BYTE(*src)) {
-			src++;
-		}
-		c++; src++;
+int utf8_next_codepoint(const char **msg) {
+	int code;
+	const unsigned char *s = (const unsigned char *)*msg;
+
+	if (*s <= 0x7f) {
+		code = *s++;
+	} else if (*s <= 0xbf) {
+		// Invalid UTF-8 sequence
+		code = '?';
+		s++;
+	} else if (*s <= 0xdf) {
+		code = (s[0] & 0x1f) << 6 | (s[1] & 0x3f);
+		s += 2;
+	} else if (*s <= 0xef) {
+		code = (s[0] & 0xf) << 12 | (s[1] & 0x3f) << 6 | (s[2] & 0x3f);
+		s += 3;
+	} else if (*s <= 0xf7) {
+		code = (s[0] & 0x7) << 18 | (s[1] & 0x3f) << 12 | (s[2] & 0x3f) << 6 | (s[3] & 0x3f);
+		s += 4;
+	} else {
+		code = 0xfffd;  // REPLACEMENT CHARACTER
+		s++;
+		while (0x80 <= *s && *s <= 0xbf)
+			s++;
 	}
-	return c;
+	*msg = (const char *)s;
+	return code;
+}
+
+char *advance_char(const char *s, CharacterEncoding e) {
+	switch (e) {
+	case SHIFT_JIS:
+		return (char *)s + ((CHECKSJIS1BYTE(*s) && *(s + 1)) ? 2 : 1);
+	case UTF8:
+		while (UTF8_TRAIL_BYTE(*++s))
+			;
+		return (char *)s;
+	}
+	return NULL;
 }
diff --git a/src/utfsjis.h b/src/utfsjis.h
index 67a1baf..c771d54 100644
--- a/src/utfsjis.h
+++ b/src/utfsjis.h
@@ -26,12 +26,30 @@
 
 #include "portab.h"
 
+typedef enum {
+	SHIFT_JIS,
+	UTF8,
+	CHARACTER_ENCODING_MAX = UTF8
+} CharacterEncoding;
+
+#define MAX_SJIS_BYTES_PAR_CHAR 2
+#define MAX_UTF8_BYTES_PAR_CHAR 4
+#define MAX_BYTES_PAR_CHAR(encoding) \
+	((encoding) == SHIFT_JIS ? MAX_SJIS_BYTES_PAR_CHAR : MAX_UTF8_BYTES_PAR_CHAR)
+
+#define UTF8_TRAIL_BYTE(b) ((signed char)(b) < -0x40)
 #define CHECKSJIS1BYTE(b) ( ((b) & 0xe0) == 0x80 || ((b) & 0xe0) == 0xe0 )
 
+extern char* codeconv(CharacterEncoding tocode,
+					  CharacterEncoding fromcode,
+					  const char *str);
+
 extern BYTE*   sjis2utf(const BYTE *src);
 extern BYTE*   utf2sjis(const BYTE *src);
 extern boolean sjis_has_hankaku(const BYTE *src);
 extern boolean sjis_has_zenkaku(const BYTE *src);
-extern int     sjis_count_char(const BYTE *src);
+extern int     utf8_next_codepoint(const char **msg);
+
+extern char *advance_char(const char *s, CharacterEncoding e);
 
 #endif /* __UTFSJIS__ */
diff --git a/src/variable.c b/src/variable.c
index 57f24ea..2a43614 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -45,7 +45,7 @@ int strvar_len = STRVAR_LEN;
 
 static char *advance(const char *s, int n) {
 	while (*s && n > 0) {
-		s += (CHECKSJIS1BYTE(*s) && *(s + 1)) ? 2 : 1;
+		s = advance_char(s, nact->encoding);
 		n--;
 	}
 	return (char *)s;
@@ -175,7 +175,14 @@ void v_strcat(int no, const char *str) {
 
 /* 文字変数の長さ */
 size_t v_strlen(int no) {
-	return sjis_count_char(v_str(no));
+	const char *s = v_str(no);
+
+	int c = 0;
+	while (*s) {
+		s = advance_char(s, nact->encoding);
+		c++;
+	}
+	return c;
 }
 
 /* Width of a string (2 for full-width characters, 1 for half-width) */
@@ -207,7 +214,7 @@ int v_strstr(int no, int start, const char *str) {
 		return -1;
 	int n = start;
 	while (p < found) {
-		p += CHECKSJIS1BYTE(*p) ? 2 : 1;
+		p = advance_char(p, nact->encoding);
 		n++;
 	}
 	return n;