This is Zsh with EUC encoding support.

The patches are mostly based on the work by ono@ono.org (Thanks!):

WWW:	http://www.ono.org/software/zsh-euc/

What I did over this is disable the hack for non-EUC locales.  Maybe
the patches can be moved to shells/zsh in the future, but it's
premature for the moment.

Notes:
- forward-char, backward-char and backward-delete-char with no numeric
  argument should work properly with this hack.
- Completion and redisplay should work fine.
- There can be some trivial side-effects if a line includes EUC
  characters. (cut'n'paste does not work properly, etc.)
- JIS X0201-Roman and JIS X0208-Kanji are supported.
- JIS X0201-Katakana and JIS X0212 Kanji are NOT supported.
- Only tested with the EUC-JP (ja_JP.eucJP) locale.  I'm not sure if
  it works for GB 2312/CNS 11643-1/KS X 1001.  Any feedbacks is
  welcome, especially a patch if it does not work. :)
- This is just a hack.  Zsh's line editor apparently needs a rewrite
  in order to support multibyte encodings properly.