It doesn't really work because Fuyuki would never be friends with someone who hurt Eri. That friend was the one who told everyone about Eri's rejecting her and added the "gross" comment. It also makes no sense for Eri to not recognize her.Could it be that senpai is the the friend that were in love with Eri-chan? I mean, they're the same age. And senpai seems to have the same kind of bad experience with love. Or I'm just reading things too hard LOL