Is there any possibility Mai-chan and Nanao are the same person?
she isn't we have seen Mai-chan already and she is working at the brothel Asumi frequents, she just hasn't gotten a reservation from Asumi so they haven't found eachother yet. Nanao really is just someone else.
Mai did get a reservation from Asumi, but was forced to cancel it because she got sick. Or was it Asumi that got sick? I'm more sure that Mai was the one that got sick, but I'm nevertheless not completely sure.
re-read it recently-ish. got a very good reminder over why it's my all-time favourite. the story, the art, the characters, everything... I think the more I times I read this, the more I'd see it as a timeless classic.