I'm using CrunchBang (#!) and I find Japanese fonts missing. To configure Japanese locale in Debian do the following.

1. Install the following:

sudo apt-get install ttf-kochi-gothic ttf-kochi-mincho ttf-sazanami-mincho xfonts-intl-japanese

2. Now we need to reconfigure the locale.

sudo dpkg-reconfigure locales

In the locales to be generated dialog box, choose ja_JP.UTF-8 UTF-8. If using English, choose en_GB.UTF-8 UTF-8 or en_US.UTF-8 UTF-8, whichever is appropriate and click Ok. Next choose the default locale.

3. Reboot (or logout session, whichever works).