Installing different language on phone Is it possible to install a different language other than the ones already in the system? I want my phone to display in Japanese. Everything...the menus, status bars, labels. Just as if my phone was made in and for Japanese.
Well, your device is bundled with Japanese language support. I think this was started with 2.1 release. If you are using an older version of android (like 2.1 or so), you might want to check this thread on XDA.

If you have a later version of android, simply go to your language settings and select Japanese as @ce4 suggested

There is no need to install Japanese language in your device.