diff -x .svn -upr mlterm-3.8.0.org/vtemu/vt_screen.c mlterm-3.8.0/vtemu/vt_screen.c
--- mlterm-3.8.0.org/vtemu/vt_screen.c	2017-01-08 07:24:38.000000000 +0900
+++ mlterm-3.8.0/vtemu/vt_screen.c	2017-03-08 20:26:25.424912000 +0900
@@ -5,6 +5,7 @@
 #include <stdlib.h> /* abs */
 #include <unistd.h> /* write */
 #include <sys/time.h>
+#include <arpa/inet.h>
 #include <pobl/bl_debug.h>
 #include <pobl/bl_mem.h>  /* malloc/free */
 #include <pobl/bl_str.h>  /* strdup */
@@ -44,25 +45,135 @@ static int get_n_prev_char_pos(vt_screen
 }
 
 static int is_word_separator(vt_char_t *ch) {
-  char *p;
-  char c;
+	switch (vt_char_cs(ch)) {
+	case ISO646_IRV:
+	case ISO646_EN:
+	case US_ASCII:
+	case JISX0201_ROMAN:
+		{
+			const char c = vt_char_code(ch);
+			char* p = word_separators;
+			for (; *p; ++ p) {
+				if (c == *p) {
+					return 1;
+				}
+			}
+			return 0;
+		}
+		break;
+
+	case JISX0208_1983:
+	case JISX0208_1983_MAC_EXT:
+	case JISX0208_1990:
+	case JISX0212_1990:
+	case JISX0213_2000_1:
+	case JISX0213_2000_2:
+		{
+			const uint16_t c = vt_char_code(ch) & 0x7F7FUL;
+			if (c <= 0x227F) {
+				switch (c) {
+				default:
+					return -2;	/* Sign */
+				case 0x212B:
+				case 0x212C:
+				case 0x2133:
+				case 0x2134:
+				case 0x2135:
+				case 0x2136:
+				case 0x2137:
+				case 0x2138:
+				case 0x2139:
+				case 0x213A:
+				case 0x213C:
+					return -1;	/* JP */
+				}
+			} else if (c <= 0x237F) {
+				return -3;	/* English */
+			} else if (c <= 0x257F) {
+				return -1;	/* JP */
+			} else if (c <= 0x267F) {
+				return -4;	/* Greek */
+			} else if (c <= 0x277F) {
+				return -5;	/* Cyrillic */
+			} else if (c <= 0x2F7F) {
+				return -6;	/* Sign, Extended */
+			}
+			return -1;	/* JP */
+		}
+		break;
+
+	case ISO10646_UCS2_1:
+	case ISO10646_UCS4_1:
+		{
+			const uint32_t c = vt_char_code(ch);
+			if (c <= 0x0033FF) {
+				if (c <= 0x00037F) {
+					return -16;	/* ? */
+				} else if (c <= 0x0003FF) {
+					return -15;	/* ? */
+				} else if (c <= 0x00052F) {
+					return -14;	/* ? */
+				} else if (c <= 0x0006FF) {
+					return -13;	/* ? */
+				} else if (c <= 0x0008FF) {
+					return -12;	/* ? */
+				} else if (c <= 0x000FFF) {
+					return -11;	/* Thai */
+				} else if (c <= 0x0010FF) {
+					return -10;	/* ? */
+				} else if (c <= 0x0011FF) {
+					return -1;	/* Korea */
+				} else if (c <= 0x0016FF) {
+					return -9;	/* ? */
+				} else if (c <= 0x001CFF) {
+					return -6;	/* ? */
+				} else if (c <= 0x001DFF) {
+					return -8;	/* ? */
+				} else if (c <= 0x001FFF) {
+					return -7;	/* German? */
+				} else if (c <= 0x00303F) {
+					return -6;	/* Sign */
+				} else if (c <= 0x0030FF) {
+					return -1;	/* JP */
+				} else if (c <= 0x00318F) {
+					return -1;	/* Korea */
+				} else if (c <= 0x0031EF) {
+					return -6;	/* Sign */
+				} else if (c <= 0x0031FF) {
+					return -1;	/* JP */
+				}
+				return -6;	/* Sign */
+			} else if (c <= 0x004DFF) {
+				return -1;	/* CJK KANJI Extended-A */
+			} else if (c <= 0x009FFF) {
+				return -1;	/* CJK KANJI */
+			} else if (c <= 0x00ABFF) {
+				return -17;	/* ? */
+			} else if (c <= 0x00D7AF) {
+				return -1;	/* Korea, Precomposed Character */
+			} else if (c <= 0x00F8FF) {
+				return -17;	/* ? */
+			} else if (c <= 0x00FAFF) {
+				return -1;	/* CJK KANJI Compatible */
+			} else if (c <= 0x00FEFF) {
+				return -17;	/* ? */
+			} else if (c <= 0x00FFFF) {
+				return -3;	/* Full Width */
+			} else if (c <= 0x01FFFF) {
+				return -17;	/* ? */
+			} else if (c <= 0x02A6FF) {
+				return -1;	/* CJK KANJI Extended-B */
+			} else if (c <= 0x02F7FF) {
+				return -17;	/* ? */
+			} else if (c <= 0x02FA1F) {
+				return -1;	/* CJK KANJI Additional */
+			}
+			return -17;	/* ? */
+		}
+		break;
+	}
 
-  if (vt_char_cs(ch) != US_ASCII) {
-    return 0;
-  }
-
-  p = word_separators;
-  c = vt_char_code(ch);
-
-  while (*p) {
-    if (c == *p) {
-      return 1;
-    }
-
-    p++;
-  }
-
-  return 0;
+	return 0;
 }
 
 /*
@@ -1149,6 +1260,8 @@ int vt_screen_get_word_region(vt_screen_
   vt_line_t *base_line;
   vt_char_t *ch;
   int flag;
+  int flag_detail ;
+  int flag_detail_tmp ;
 
   if ((base_line = vt_screen_get_line(screen, base_row)) == NULL || vt_line_is_empty(base_line)) {
     return 0;
@@ -1200,7 +1313,8 @@ int vt_screen_get_word_region(vt_screen_
     }
   }
 
-  if (is_word_separator(vt_char_at(base_line, base_char_index))) {
+  flag_detail = is_word_separator(vt_char_at(base_line, base_char_index));
+  if (0 < flag_detail) {
     *beg_char_index = base_char_index;
     *end_char_index = base_char_index;
     *beg_row = base_row;
@@ -1235,7 +1349,8 @@ int vt_screen_get_word_region(vt_screen_
 
     ch = vt_char_at(line, char_index);
 
-    if (is_word_separator(ch) || flag != vt_char_is_fullwidth(ch)) {
+    flag_detail_tmp = is_word_separator(ch);
+    if (0 < flag_detail_tmp || flag != vt_char_is_fullwidth(ch) || flag_detail != flag_detail_tmp) {
       *beg_char_index = char_index + 1;
 
       break;
@@ -1268,7 +1383,8 @@ int vt_screen_get_word_region(vt_screen_
 
     ch = vt_char_at(line, char_index);
 
-    if (is_word_separator(ch) || flag != vt_char_is_fullwidth(ch)) {
+    flag_detail_tmp = is_word_separator(ch);
+    if (0 < flag_detail_tmp || flag != vt_char_is_fullwidth(ch) || flag_detail != flag_detail_tmp) {
       *end_char_index = char_index - 1;
 
       break;