@boag Does it?
It's been awhile since I read through this, but so far the MC has only been attracted to this one person, right? This seems closer to demisexuality than homosexuality. I'm certainly not the authority, but it doesn't feel like they're using the label appropriately.
I may very well be wrong definitionally, but even so I can think of numerous shows and films that do a far better job of making homosexual people relatable. It's played for laughs in this story, but Rei's behavior is not relatable at all. What do we call people who constantly subject others to unwanted physical contact? I hope you don't think it's "relatable."
EDIT - And if we separate Rei's inappropriate behavior from her sexuality (which is fine), then there's nothing left to her character, she is entirely one-dimensional.