diff --git a/scim-wnn/src/romkan.cpp b/scim-wnn/src/romkan.cpp
index db4d14a..36aa55b 100644
--- a/scim-wnn/src/romkan.cpp
+++ b/scim-wnn/src/romkan.cpp
@@ -32,7 +32,6 @@
 }
 
 
-
 /*!
     \fn Romkan::getPos()
  */
@@ -125,12 +124,12 @@
     // �ơ��֥�򸡺��������Ϥ��롣
     unsigned int i = 0;
     while(RomkanTable[i] != "") {
-        if (buf == RomkanTable[i]) {
-            if (RomkanTable[i + 1] == "") {
+        if (buf == String(RomkanTable[i])) {
+            if (String(RomkanTable[i + 1]) == "") {
                 return(text); // ��α���롣
             }
             WideString w;
-            iconvert.convert(w,RomkanTable[i + 1]);
+            iconvert.convert(w,String(RomkanTable[i + 1]));
             text = text.substr(0,pos - buf.length()) + w + text.substr(pos);
             pos = pos - buf.length() + w.length();
             buf.clear();
@@ -193,3 +192,56 @@
     if (getPos() == getTextLength()) return;
     text = text.substr(0,pos) + text.substr(pos + 1);
 }
+
+
+/*!
+    \fn Romkan::convHiraKata(WideString &t)
+ */
+void Romkan::convHiraKata(WideString &t)
+{
+    WideString start_c,end_c,conv_c;
+    iconvert.convert(start_c,String("��"));
+    iconvert.convert(end_c,String("��"));
+    iconvert.convert(conv_c,String("��"));
+    for(unsigned int i = 0;i < t.size();i ++) {
+        if ((t[i] >= start_c[0]) && (t[i] <= end_c[0]))
+            t[i] = t[i] - start_c[0] + conv_c[0];
+    }
+    return;
+}
+
+
+/*!
+    \fn Romkan::convKataHira(WideString &t)
+ */
+void Romkan::convKataHira(WideString &t)
+{
+    WideString start_c,end_c,conv_c;
+    iconvert.convert(start_c,String("��"));
+    iconvert.convert(end_c,String("��"));
+    iconvert.convert(conv_c,String("��"));
+    for(unsigned int i = 0;i < t.size();i ++) {
+        if ((t[i] >= start_c[0]) && (t[i] <= end_c[0]))
+            t[i] = t[i] - start_c[0] + conv_c[0];
+    }
+    return;
+
+}
+
+
+/*!
+    \fn Romkan::hiraKata()
+ */
+void Romkan::hiraKata()
+{
+    convHiraKata(text);
+}
+
+
+/*!
+    \fn Romkan::kataHira()
+ */
+void Romkan::kataHira()
+{
+    convKataHira(text);
+}
diff --git a/scim-wnn/src/romkan.h b/scim-wnn/src/romkan.h
index f0a9d89..649d4be 100644
--- a/scim-wnn/src/romkan.h
+++ b/scim-wnn/src/romkan.h
@@ -21,9 +21,11 @@
 #define ROMKAN_H
 
 #define Uses_SCIM_ICONV
+#include <vector>
 #include <scim.h>
 #include <scim_iconv.h>
 
+using namespace std;
 using namespace scim;
 
 /**
@@ -44,6 +46,10 @@
     WideString getText(bool hosei = false);
     void backspace();
     void del();
+    void convHiraKata(WideString &t);
+    void convKataHira(WideString &t);
+    void hiraKata();
+    void kataHira();
 
 protected:
     WideString text;
diff --git a/scim-wnn/src/romkan_table.h b/scim-wnn/src/romkan_table.h
index e7511bc..cd6795d 100644
--- a/scim-wnn/src/romkan_table.h
+++ b/scim-wnn/src/romkan_table.h
@@ -21,7 +21,7 @@
 // ���޻������Ѵ��ơ��֥롣
 // �������ʤΤǥߥ�/��­�β�ǽ�����ꡣ
 
-String RomkanTable[] = {
+const char RomkanTable[][6] = {
 //  "�ɤ�",   "�Ѵ�",
 //  ("�Ѵ�"������ξ�����α��"�ɤ�"����ϥ����ߥ͡���)
     "a",    "��",
diff --git a/scim-wnn/src/scim_wnn_def.h b/scim-wnn/src/scim_wnn_def.h
index 4a9e40e..45e9ea2 100644
--- a/scim-wnn/src/scim_wnn_def.h
+++ b/scim-wnn/src/scim_wnn_def.h
@@ -53,6 +53,10 @@
 #define SCIM_DEFAULT_WNN_KEY_LOOKUPPAGEUP           "Page_Up"
 #define SCIM_CONFIG_WNN_KEY_LOOKUPPAGEDOWN          "/IMEngine/Wnn/Key/LookupPageDown"
 #define SCIM_DEFAULT_WNN_KEY_LOOKUPPAGEDOWN         "Page_Down"
+#define SCIM_CONFIG_WNN_KEY_CONVERT_HIRAGANA        "/IMEngine/Wnn/Key/ConvertHiragana"
+#define SCIM_DEFAULT_WNN_KEY_CONVERT_HIRAGANA       "Alt+h"
+#define SCIM_CONFIG_WNN_KEY_CONVERT_KATAKANA        "/IMEngine/Wnn/Key/ConvertKatakana"
+#define SCIM_DEFAULT_WNN_KEY_CONVERT_KATAKANA       "Alt+k"
 
 #define SCIM_CONFIG_WNN_ALP                         "/IMEngine/Wnn/AutoLookupPopup"
 #define SCIM_DEFAULT_WNN_ALP                        3
diff --git a/scim-wnn/src/scim_wnn_imengine.cpp b/scim-wnn/src/scim_wnn_imengine.cpp
index 64b5207..448ec96 100644
--- a/scim-wnn/src/scim_wnn_imengine.cpp
+++ b/scim-wnn/src/scim_wnn_imengine.cpp
@@ -250,6 +250,12 @@
     scim_string_to_key_list(k_lookup_pagedown,
         _scim_config->read(String(SCIM_CONFIG_WNN_KEY_LOOKUPPAGEDOWN),
             String(SCIM_DEFAULT_WNN_KEY_LOOKUPPAGEDOWN)));
+    scim_string_to_key_list(k_convert_hiragana,
+        _scim_config->read(String(SCIM_CONFIG_WNN_KEY_CONVERT_HIRAGANA),
+            String(SCIM_DEFAULT_WNN_KEY_CONVERT_HIRAGANA)));
+    scim_string_to_key_list(k_convert_katakana,
+        _scim_config->read(String(SCIM_CONFIG_WNN_KEY_CONVERT_KATAKANA),
+            String(SCIM_DEFAULT_WNN_KEY_CONVERT_KATAKANA)));
 
 }
 
@@ -329,6 +335,24 @@
         hide_preedit_string();
         return(true);
     } else
+    if (k_convert_hiragana.comp(key)) {
+        if (!m_rk.getTextLength()) {
+            return(false);
+        }
+        m_rk.kataHira();
+        update_preedit_string(m_rk.getText());
+        update_preedit_caret(m_rk.getPos());
+        return(true);
+    } else
+    if (k_convert_katakana.comp(key)) {
+        if (!m_rk.getTextLength()) {
+            return(false);
+        }
+        m_rk.hiraKata();
+        update_preedit_string(m_rk.getText());
+        update_preedit_caret(m_rk.getPos());
+        return(true);
+    } else
     if (isprint(key.code)) {
         if (key.mask & (SCIM_KEY_AltMask | SCIM_KEY_ControlMask)) return(false);
         show_preedit_string();
diff --git a/scim-wnn/src/scim_wnn_imengine.h b/scim-wnn/src/scim_wnn_imengine.h
index 9e1e05a..eef64f3 100644
--- a/scim-wnn/src/scim_wnn_imengine.h
+++ b/scim-wnn/src/scim_wnn_imengine.h
@@ -115,6 +115,8 @@
         k_lookup_popup,         // �������ɽ��
         k_lookup_pageup,        // �����������
         k_lookup_pagedown,      // �����������
+        k_convert_hiragana,     // �Ҥ餬���Ѵ�
+        k_convert_katakana,     // ���������Ѵ�
         k_dummy;
 
 };