Is the Japanese game really in Bilingual?
User reports have stated that if you start a new game with your DS language as Japanese, you can play the game in Japanese. However, if you start a new game with the DS language in English, the game will be displayed in English. Apparently, changing the language setting in the middle of a game will do nothing to the in-game language. It must be done before you start a new game. In other words, if you are halfway through playing the game in English and you want to change it to Japanese, youll have to change your DS language to Japanese then start a new game in order for the change to take effect.