As far as fun goes, she is my top fav of fun girl in this show, as far as something mysterious goes, I think Chisato scores high, I like her because she's pretty, and the boob grab Jima did in the morning didn't actually bother her so I guess she loves him a lot.
I have a feeling her Chocolate thing is something not traumatic, just important. Discovering that might be interesting.
I do understand the girl that wants to shut down some clubs, but she doesn't understand why those clubs were formed in the first place, which makes her point of view invalid.