It's sort of an Board Game/Adventure/RPG. You build your party of delinquent girls and then walk around town trying to solve a mystery, like a chain-smoking Nancy Drew. Instead of combat, when you have an "encounter" you have to get out of it by doing stuff like flirting (if it's a guy) or trash-talking (if it's another girl) or lying or whatever the situation calls for. All the encounters are handled by minigames, but you can build up your girl's stats to make certain minigames easier (if you're levels are too low, they can be impossible). Failing the minigames can make you faint (die) for a few turns, and that that character is unusable. A typical situation might be that you've found out something suspicious is going on in the gym, but it's locked and you need to get the key from the vice principal, so you talk to him and he asks you why you want it, and you have to lie and say you're decorating for home coming, so you do the Lying minigame and if you win you get the key, and if you lose then you lose a day and you have to try to borrow a crowbar from the janitor on the next day or something.
The writing is really good. Pretty funny and it's full of 1920's slang. It has pretty good replay value since you can choose different paths and talk to different people.