Patch to utf-tool.el for >= emacs-23. Replace only CJK characters.

utf-tool-23-cjk.patch

--- utf-tool.el.orig    2013-02-24 15:24:54.914062345 +0900
+++ utf-tool.el 2013-02-24 15:23:21.947814237 +0900
@@ -58,11 +58,13 @@
            ;; (charset-description charset)
            ;; (split (split-char char))
            (pos (point))
-           (unicode nil))
+           (unicode nil)
+           (cjk (string-match "CJK" (get-char-code-property char 'name))))
       (unless
-          (memq charset '(ascii japanese-jisx0208 katakana-jisx0201))
+          (or (memq charset '(ascii japanese-jisx0208 katakana-jisx0201))
+              (not cjk))
         (if (or (< char 256)
-                (memq 'mule-utf-8 (find-coding-systems-region pos (1+ pos)))
+                (memq 'utf-8 (find-coding-systems-region pos (1+ pos)))
                 (get-char-property pos 'untranslated-utf-8))
             (setq unicode (or (get-char-property pos 'untranslated-utf-8)
                               (encode-char char 'ucs))))