Literally my only problem is that one of them is the stereotypical psycho lesbian.
Seriously, why are psychotic/psychopathic lesbians a trope?
Honestly, Yutaka is one of my favourite characters, basically because she's the only person who consistently understands what's going on, realises how everyone else is misunderstanding things, and acts logically. Even her not confessing to Matsuri before makes sense, considering the fact that Matsuri is so obsessed with Toramaru that she tried to murder Unoki with a knife in broad daylight right outside the school. It's not exactly unreasonable to think someone you've been close friends with since childhood isn't interested in you when it gets to that point.