I have no idea if Rei and Hina are the romance tag inducing couple of this series, but if they are, I find their relationship quite quaintly interesting, compared to most of the manga I've read. It would almost be like a childhood friend winning, despite those two not being childhood friends. There would be no dramatic falling in love, like the carpet getting pulled from under someone's feet. It would be a subtle realisation sort of thing. Hina is quite emotional and energetic, so it would be even more interesting for her to end up like that. Aftr all, he crush on Takahashi was very much the fangirl kind of idolising love. Loving someone romantically has probably never even visited Rei's mind. He was too emotionally isolated for that not long ago, plus I think feeling sick while watching the Kyoko+Gotou "romance" didn't exactly make him eager for a romance of his own.