japanese-hankaku-region
japanese-hankaku-region is an interactive autoloaded Lisp function in `japan-util.el
'.
(japanese-hankaku-region FROM TO &optional ASCII-ONLY)
Convert Japanese `zenkaku' chars in the region to `hankaku' chars.
`Zenkaku' chars belong to `japanese-jisx0208'
`Hankaku' chars belong to `ascii' or `japanese-jisx0201-kana'.
Optional argument ASCII-ONLY non-nil means to convert only to ASCII char.