Basically, you chat to girls to find out about them, which give you “Hunie” points. You then go on dates with the girls which consists of a match-3 puzzle game. The dates give you “Munie”. You spend this money on gifts for the girls which generates more Hunie, and you spend the Hunie on stat improvements for yourself which makes your match-3 abilities more powerful in various ways. And round and round it goes. It works surprisingly well, and even without the very naughty girls in it the mechanics are much better than in many other similar games.
After you’ve successfully dated each girl four times, you get to take her home. Take all the girls home, and you win the game (and at life, presumably). So I did that. Apparently there are two more secret girls to find somewhere, but I’ve no idea where.