Text messaging in Asian languages

Watching the Olympics with my girlfriend the other night there was a shot of one of the Japanese figure skaters appearing to be texting on a cell phone. Whether she was texting in English or Japanese was not clear, but we went ahead and assumed it was in Japanese. Anyway, my girlfriend wondered how this would be accomplished and after some rudimentary research I decided the best option would be to put it to the SD’s TM.

So who knows how one texts in kanji? Is there a special code involved, or some kind of super-advanced T9 system? Could you do it with a standard numerical keypad or does it require a phone with a full keyboard?