According to ESRB, this game contains: Alcohol Reference, Language, Mild Fantasy Violence
Parents, you're on your own with this one. I could see the "mild fantasy violence" from the pathetic battles that looked more like a crowd of people milling around than any sort of fighting, but I can't speak to the rest of it. There may be alcohol references and language, but the game was so confusing and such a mess that I could not finish it or even make much progress. If your kids can figure this game out, put them into your school's "gifted" program and start saving up for college.
Gifted kids—stay away. And, if for some reason you do get this game and you like it, tell your parents to start saving up for behavioral therapy.
Everyone else, this is the worst game I have played on PSP, bar none. With no instruction, no tutorial, and absolutely no way to tell what is going on or what the point of the game is, the experience is more frustrating than trying to learn Japanese while stuck inside a soundproof booth.
Deaf and Hard of Hearing gamers should stay away because the game is rotten, but if for some crazy reason they do decide to pick this up, know that there are subtitles for all the dialogue in game. I can't say for a fact that there are no significant auditory cues, but my impression is that the game is totally stat-based and methodical, so my guess is that there aren't.