haha I'm not sure. There is a certain level of concentration involved and they're both good/decent at that. But there's memorization involved (which Rin is probably okay at, not sure about Haru) as well as having to put any cards bumped out of place in the right place after every round which could easily irritate them both before too long. So I think it depends on whether they have enough competitive spirit to get though a game which could go either way.