Hello again and have a bit more easier and logical one how about an interract able mini-game which can help either build up relationship with the girls a bit or just a cool thing to play when bored like 2048 or a memory game or even and quick shooter(like hit the target as quick and as many as possible) game or even a maze/quiz solving on one of arcades
You could use this as a way for like you know bets and the loser has to do what the other days like do exercises or prank someone or 'service'(sorry could not help myself) but the that's it