I think you should elaborate a little more anyway. I can say that Otoyomegatari can enable a debate on arranged marriages, which is a serious topic, but I don't think it's what you're referring, right?
________________ What I like in Trivial Pursuit style. Pick your category:
If you mean something that will make you think.... ...try Olimpos, which has got this thing with immortality (I don't know, might not be your cup of tea, with all the sparkly, androgynous characters and whatnot). I will say this though: If I read it impatiently, I would have hated it (but I had a book report to do that I didn't want to, so I took my time ).