diff --git a/honoka/libhonoka/convertor.h b/honoka/libhonoka/convertor.h
index 666e546..d61b2e4 100644
--- a/honoka/libhonoka/convertor.h
+++ b/honoka/libhonoka/convertor.h
@@ -36,10 +36,13 @@
 using namespace std;
 using namespace scim;
 
+
 /**
 @author TAM (Teppei Tamra)
 */
 
+namespace Honoka {
+
 class Segment {
 public:
     Segment(const WideString _kanji,const WideString _yomi);
@@ -80,4 +83,6 @@
 
 };
 
+}
+using namespace Honoka;
 #endif
diff --git a/honoka/libhonoka/honokakeyeventlist.h b/honoka/libhonoka/honokakeyeventlist.h
index dcdb516..f18d45b 100644
--- a/honoka/libhonoka/honokakeyeventlist.h
+++ b/honoka/libhonoka/honokakeyeventlist.h
@@ -34,6 +34,8 @@
 /**
 @author TAM (Teppei Tamra)
 */
+
+namespace Honoka {
 class HonokaKeyEventList : public KeyEventList
 {
 public:
@@ -43,4 +45,8 @@
 
 };
 
+}
+
+using namespace Honoka;
+
 #endif
diff --git a/honoka/libhonoka/honokamultiplepluginbase.h b/honoka/libhonoka/honokamultiplepluginbase.h
index 5b7755f..148690b 100644
--- a/honoka/libhonoka/honokamultiplepluginbase.h
+++ b/honoka/libhonoka/honokamultiplepluginbase.h
@@ -37,6 +37,9 @@
 /**
 @author TAM (Teppei Tamra)
 */
+
+namespace Honoka {
+
 class HonokaMultiplePluginBase : public HonokaPluginBase {
 public:
     HonokaMultiplePluginBase(ConfigPointer cfg);
@@ -50,4 +53,8 @@
     ConfigPointer config;
 };
 
+}
+
+using namespace Honoka;
+
 #endif
diff --git a/honoka/libhonoka/honokapluginbase.h b/honoka/libhonoka/honokapluginbase.h
index 9ff5376..fe3a570 100644
--- a/honoka/libhonoka/honokapluginbase.h
+++ b/honoka/libhonoka/honokapluginbase.h
@@ -27,7 +27,7 @@
 #include <scim.h>
 #define Uses_SCIM_CONFIG_BASE
 
-#define HONOKA_PLUGIN_VERSION 3
+#define HONOKA_PLUGIN_VERSION 4
 
 using namespace std;
 using namespace scim;
@@ -36,6 +36,8 @@
 @author TAM (Teppei Tamra)
 */
 
+namespace Honoka {
+
 #define HonokaPluginRegister(pName) \
     extern "C" { \
         HonokaPluginBase *getHonokaPluginInstance(ConfigPointer cfg) { return new pName(cfg); } \
@@ -57,4 +59,8 @@
     String type;
 };
 
+}
+
+using namespace Honoka;
+
 #endif
diff --git a/honoka/libhonoka/predictor.h b/honoka/libhonoka/predictor.h
index 31dcda0..a2f18fa 100644
--- a/honoka/libhonoka/predictor.h
+++ b/honoka/libhonoka/predictor.h
@@ -40,6 +40,9 @@
 /**
 @author TAM (Teppei Tamra)
 */
+
+namespace Honoka {
+
 class Predictor : public HonokaPluginBase {
 public:
     Predictor(ConfigPointer cfg);
@@ -54,4 +57,8 @@
     virtual void update(const WideString str,const WideString yomi);
 };
 
+}
+
+using namespace Honoka;
+
 #endif
diff --git a/honoka/libhonoka/preeditor.h b/honoka/libhonoka/preeditor.h
index d79566f..bc62090 100644
--- a/honoka/libhonoka/preeditor.h
+++ b/honoka/libhonoka/preeditor.h
@@ -55,6 +55,8 @@
 @author TAM(Teppei Tamra)
 */
 
+namespace Honoka {
+
 class PreEditor : public HonokaPluginBase {
 public:
     PreEditor(ConfigPointer cfg);
@@ -98,4 +100,8 @@
 
 };
 
+}
+
+using namespace Honoka;
+
 #endif
diff --git a/honoka/libhonoka/resultlist.h b/honoka/libhonoka/resultlist.h
index d6af158..5562f62 100644
--- a/honoka/libhonoka/resultlist.h
+++ b/honoka/libhonoka/resultlist.h
@@ -37,6 +37,8 @@
 @author TAM (Teppei Tamra)
 */
 
+namespace Honoka {
+
 enum ResultType { DEFAULT,PREDICTION,SPECIAL1,SPECIAL2,SPECIAL3,SPECIAL4 };
 
 class ResultEntry {
@@ -58,4 +60,8 @@
     vector<ResultEntry> kouho;
 };
 
+}
+
+using namespace Honoka;
+
 #endif
diff --git a/honoka/src/Makefile.am b/honoka/src/Makefile.am
index c5aa834..6da3a2d 100644
--- a/honoka/src/Makefile.am
+++ b/honoka/src/Makefile.am
@@ -27,7 +27,7 @@
 			  -DHONOKA_PLUGINDIR=\"@SCIM_MODULEDIR@/honoka\"
 
 noinst_HEADERS = honoka_imengine.h 				multiconvertor.h honoka_def.h \
-		honokasetupgtk.h acpredictor.h
+			honokasetupgtk.h acpredictor.h
 
 moduledir		= @SCIM_MODULEDIR@/IMEngine
 module_LTLIBRARIES	= honoka.la