diff --git a/scim-wnn/data/like-msime.rkt b/scim-wnn/data/like-msime.rkt
index 38d5648..90dd0f0 100644
--- a/scim-wnn/data/like-msime.rkt
+++ b/scim-wnn/data/like-msime.rkt
@@ -8,6 +8,11 @@
 # Ascii/WideAsciiモードへの移行キー。
 $Key/Ascii      null
 $Key/WideAscii  null
+# 全角/半角トグルキー
+$Key/ToggleHalfOrWide   Zenkaku_Hankaku
+
+!Shift+space    　# 全角スペース
+
 -       ー
 a       あ
 i       い
diff --git a/scim-wnn/src/preeditor.cpp b/scim-wnn/src/preeditor.cpp
index f24c796..e628ac4 100644
--- a/scim-wnn/src/preeditor.cpp
+++ b/scim-wnn/src/preeditor.cpp
@@ -201,23 +201,23 @@
 
 
 /*!
-    \fn PreEditor::convHanZen(WideString &t,int &p)
+    \fn PreEditor::convHanZen(WideString &t,int p)
  */
-void PreEditor::convHanZen(WideString &t,int &p)
+int PreEditor::convHanZen(WideString &t,int p)
 {
     for(unsigned int i = 0;i < t.size();i ++) {
         if ((t[i] >= convChars[ASCII_START]) && (t[i] <= convChars[ASCII_END]))
             t[i] = t[i] - convChars[ASCII_START] + convChars[WASCII_START];
     }
-    return;
+    return(p);
 
 }
 
 
 /*!
-    \fn PreEditor::convZenHan(WideString &t,int &p)
+    \fn PreEditor::convZenHan(WideString &t,int p)
  */
-void PreEditor::convZenHan(WideString &t,int &p)
+int PreEditor::convZenHan(WideString &t,int p)
 {
     for(unsigned int i = 0;i < t.size();i ++) {
         if ((t[i] >= convChars[WASCII_START]) && (t[i] <= convChars[WASCII_END]))
@@ -233,7 +233,7 @@
             i += it->second.length() - 1;
         }
     }
-    return;
+    return(p);
 
 }
 
diff --git a/scim-wnn/src/preeditor.h b/scim-wnn/src/preeditor.h
index 1316f67..0444ffd 100644
--- a/scim-wnn/src/preeditor.h
+++ b/scim-wnn/src/preeditor.h
@@ -79,8 +79,8 @@
     virtual String getModeName();
     static void convHiraKata(WideString &t);
     static void convKataHira(WideString &t);
-    static void convHanZen(WideString &t,int &p);
-    static void convZenHan(WideString &t,int &p);
+    static int convHanZen(WideString &t,int p);
+    static int convZenHan(WideString &t,int p);
     virtual bool cancelEvent();
     virtual bool inputEvent(const KeyEvent &key);
     virtual String getName();
diff --git a/scim-wnn/src/romkan.cpp b/scim-wnn/src/romkan.cpp
index 34e6c1a..9c02e81 100644
--- a/scim-wnn/src/romkan.cpp
+++ b/scim-wnn/src/romkan.cpp
@@ -170,6 +170,8 @@
         scim_string_to_key_list(key_ascii_mode,tableConfig["Key/Ascii"]);
     if (tableConfig.find("Key/WideAscii") != tableConfig.end())
         scim_string_to_key_list(key_wascii_mode,tableConfig["Key/WideAscii"]);
+    if (tableConfig.find("Key/ToggleHalfOrWide") != tableConfig.end())
+        scim_string_to_key_list(key_toggle_hw,tableConfig["Key/ToggleHalfOrWide"]);
     if (tableConfig.find("Hook") != tableConfig.end())
         hookp = tableConfig["Hook"];
     else hookp = "";
@@ -233,6 +235,13 @@
             return(eval());
             break;
         }
+        case HROMA: {
+            buf += s;
+            text = text.substr(0,pos) + utf8_mbstowcs(s) + text.substr(pos);
+            pos ++;
+            return(eval());
+            break;
+        }
     }
     return(text);
 }
@@ -257,14 +266,20 @@
                 if (buf[1] == b[i]) boin = true;
             }
             if (!boin) {
-                text = text.substr(0,pos - 2) + convChars[KANA_N] + text.substr(pos - 1);
+                WideString r;
+                r += convChars[KANA_N];
+                if (mode == HROMA) convZenHan(r,0);
+                text = text.substr(0,pos - 2) + r + text.substr(pos - 1);
                 buf = buf.substr(buf.length() - 1,1);
             }
         }
 
         // Ʊ��ʸ������ʸ��³���Ȥ���ϡ֤áסܻҲ��Ǥ��롣�첻��Ϣ�Ǥ�buf�˻ĤäƤϤ��ʤ��Ϥ���
         else if (buf[0] == buf[1]) {
-            text = text.substr(0,pos - 2) + convChars[KANA_XTU] + text.substr(pos - 1);
+            WideString r;
+            r += convChars[KANA_XTU];
+            if (mode == HROMA) convZenHan(r,0);
+            text = text.substr(0,pos - 2) + r + text.substr(pos - 1);
             buf = buf.substr(buf.length() - 1,1);
             return(text);
         }
@@ -275,8 +290,11 @@
     // �ơ��֥�򸡺��������Ϥ��롣
     map<String,WideString>::iterator it = RomkanTable.find(buf);
     if (it != RomkanTable.end()) {
-        text = text.substr(0,pos - buf.length()) + it->second + text.substr(pos);
-        pos = pos - buf.length() + it->second.length();
+        WideString r;
+        r += it->second;
+        if (mode == HROMA) convZenHan(r,0);
+        text = text.substr(0,pos - buf.length()) + r + text.substr(pos);
+        pos = pos - buf.length() + r.length();
         buf.clear();
         return(text);
     }
@@ -326,12 +344,18 @@
                 text = text.substr(0,pos - buf.length()) + text.substr(pos);
                 pos -= buf.length();
                 if (buf.substr(buf.length() - 1,1) == "n") {
-                    text = text.substr(0,pos) + convChars[KANA_N] + text.substr(pos);
+                    WideString r;
+                    r += convChars[KANA_N];
+                    if (mode == HROMA) convZenHan(r,0);
+                    text = text.substr(0,pos) + r + text.substr(pos);
                     pos ++;
                 }
             } else 
             if (buf.substr(buf.length() - 1,1) == "n") {
-                text = text.substr(0,pos - 1) + convChars[KANA_N] + text.substr(pos);
+                WideString r;
+                r += convChars[KANA_N];
+                if (mode == HROMA) convZenHan(r,0);
+                text = text.substr(0,pos - 1) + r + text.substr(pos);
             }
         }
     }
@@ -386,9 +410,7 @@
  */
 void Romkan::toHalf()
 {
-    int p = getPos();
-    convZenHan(text,p);
-    if (p != getPos()) setPos(p);
+    setPos(convZenHan(text,getPos()));
     buf.clear();
 }
 
@@ -397,9 +419,7 @@
  */
 void Romkan::toWide()
 {
-    int p = getPos();
-    convHanZen(text,pos);
-    if (p != getPos()) setPos(p);
+    setPos(convHanZen(text,getPos()));
     buf.clear();
 }
 
@@ -410,6 +430,28 @@
  */
 bool Romkan::keyEventHook(const KeyEvent &key)
 {
+    if (key_toggle_hw.comp(key)) {
+        switch (mode) {
+            case ASCII: {
+                mode = WASCII;
+                break;
+            }
+            case WASCII: {
+                mode = ASCII;
+                break;
+            }
+            case ROMA: {
+                mode = HROMA;
+                break;
+            }
+            case HROMA: {
+                mode = ROMA;
+                break;
+            }
+        }
+        return(true);
+    }
+    
     if ((isprint(key.code)) && ((mode == ASCII) || (mode == WASCII))) {
         if ((!key.is_alt_down()) && (!key.is_control_down())) {
             insert(key.get_ascii_code());
@@ -443,6 +485,10 @@
             return(String(_("Roma-Kana")));
             break;
         }
+        case HROMA: {
+            return(String(_("Half Roma-Kana")));
+            break;
+        }
         case ASCII: {
             return(String(_("Ascii")));
             break;
diff --git a/scim-wnn/src/romkan.h b/scim-wnn/src/romkan.h
index c54abdd..a9bb03e 100644
--- a/scim-wnn/src/romkan.h
+++ b/scim-wnn/src/romkan.h
@@ -81,12 +81,12 @@
 protected:
     String buf;
     String modeName;
-    enum inputMode {ROMA,ASCII,WASCII};
+    enum inputMode {ROMA,HROMA,ASCII,WASCII};
     inputMode mode;
     bool nnMode;
     bool asciiCancel;
     bool removeRemainder;
-    PreEditorKeyEventList key_ascii_mode,key_wascii_mode;
+    PreEditorKeyEventList key_ascii_mode,key_wascii_mode,key_toggle_hw;
     map<String,WideString> RomkanTable;
     set<String> keepTable;
     map<String,String> tableConfig;