Default [Q] Adding Japanese MUI to stock rom?

I just bought a new Galaxy Tab 3 (US Version) and couldn't find the Japanese interface selection under Settings -> Language & Input. I see Chinese, Korean and a bunch of other languages. It's running 4.2.2 on the device, model # :GT-P5210.

Is there any way to add Japanese to the tablet or would I have to flash a custom ROM to get it to display Japanese for the interface? I'm sending this to a friend in Japan.

Thanks for the help.