And just like clockwork, the angry lesbian friend is getting paired off with a male side character. To some readers, it may seem like this shouldn't happen given how Arisa has always been hating on men (particularly Masakatsu), but not in the minds of manga writers. It was either she falls for a male side character, she falls for the male lead (which only happens in harems), or she continues being the angry clingy "friend".
Seriously, this girls is so stock. At the very least it seems like she'll stop being such a jerk to Masakatsu for no good reason other than "Koyuki's mine!". At least I hope.