locale-genについて

apt-get locales

/etc/locale.genを以下のように編集し

 # This file lists locales that you wish to have built. You can find a list
 # of valid supported locales at /usr/share/i18n/SUPPORTED. Other
 # combinations are possible, but may not be well tested. If you change
 # this file, you need to rerun locale-gen.
 #
 # XXX GENERATED XXX
 #
 # NOTE!!! If you change this file by hand, and want to continue
 # maintaining manually, remove the above line. Otherwise, use the command
 # "dpkg-reconfigure locales" to manipulate this file. You can manually
 # change this file without affecting the use of debconf, however, since it
 # does read in your changes.
 
 ja_JP.EUC-JP EUC-JP
 ja_JP.SJIS SHIFT-JIS
 ja_JP.UTF-8 UTF-8

locale-genを実行するだけ。