It's a topic that keeps coming up for different characters, so here's a thread to talk about it. Do you have any favourite/least favourite reincarnation theories? Or do you hate the lot of them?
For me, I'm not a big fan of them, especially when they depend on characters being reincarnated while they're still ghosts trapped somewhere. So I don't really like the idea that Mio and Mayu are reincarnations of Yae and Sae, or that Rui is a reincarnation of Ouse, for example.
I think for a lot of the guys' stories they make more sense, like Mafuyu = Kirie's Lover, Kei = Akito, Ren = Asou, because in those cases there's the strong physical resemblance as well, but it's not like they're the only characters whose stories revolve around completing someone else's unfinished business. So even if I think it's plausible, I think Mafuyu's the only one where I'd consider it an important part of his character if true.
My favourite crack theory
by which I mean the one I came up with is that Ren and Rui are reincarnations of Kunihiko Asou and Seijiro Makabe. It makes sense, I tell you!