1. System is set with English locale.

2.  #dpkg-reconfigure locales;

generate ja_JP.UTF-8 locale (check *), while en_US.UTF-8 intct.

Select en_US.UTF-8 as system locale.

3. Check:

kiyoshi@debian-yu:~$ locale
LANG=en_US.UTF-8
LANGUAGE=
LC_CTYPE=”en_US.UTF-8″
LC_NUMERIC=”en_US.UTF-8″
LC_TIME=”en_US.UTF-8″
LC_COLLATE=”en_US.UTF-8″
LC_MONETARY=”en_US.UTF-8″
LC_MESSAGES=”en_US.UTF-8″
LC_PAPER=”en_US.UTF-8″
LC_NAME=”en_US.UTF-8″
LC_ADDRESS=”en_US.UTF-8″
LC_TELEPHONE=”en_US.UTF-8″
LC_MEASUREMENT=”en_US.UTF-8″
LC_IDENTIFICATION=”en_US.UTF-8″
LC_ALL=
kiyoshi@debian-yu:~$ locale -a
C
C.UTF-8
en_US.utf8
ja_JP.utf8
POSIX

4. Run Japanese program (not necessarily compiled in Japanese locale):

4.1.   $ LANG=ja_JP.UTF-8 ./BM;   O.K. ( ./BM is just a example)

4.2.  kiyoshi@debian-yu:~$ LANG=ja_JP.UTF-8
kiyoshi@debian-yu:~$ locale
LANG=ja_JP.UTF-8
LANGUAGE=
LC_CTYPE=”ja_JP.UTF-8″
LC_NUMERIC=”ja_JP.UTF-8″
LC_TIME=”ja_JP.UTF-8″
LC_COLLATE=”ja_JP.UTF-8″
LC_MONETARY=”ja_JP.UTF-8″
LC_MESSAGES=”ja_JP.UTF-8″
LC_PAPER=”ja_JP.UTF-8″
LC_NAME=”ja_JP.UTF-8″
LC_ADDRESS=”ja_JP.UTF-8″
LC_TELEPHONE=”ja_JP.UTF-8″
LC_MEASUREMENT=”ja_JP.UTF-8″
LC_IDENTIFICATION=”ja_JP.UTF-8″
LC_ALL=
;

Can run Japanese program.

4.3.  In .bashrc, add the following line:

export LANG=ja_JP.UTF-8

All the three above works O.K.