Honeslty? Both Noriko and Ayane irritate the hell out of me, and even for the very same reason.Well he's got a point with Noriko (ofc I am tots unbiased here ^^).
She was the better Sister and get's bonus points for creative problem solving. She also get's bonus points in the "scaring the shit outta Sensei" department but he does kinda deserve it.
Sana on the other hand is the cutest and second to none, no questions asked and Kirin ... well see below.
Yeah I couldn't even read the dialogue in that scene, goddammit.
Thing is, I actually really like Kirin as a whole and how she behaves. But what she does to Ayane is just making me hate her so fucking much. This scene was brutally uncomfortable and while I long lost any interest in fapping during any of this games H-Scenes, this one was a new high in the "no horny" department. That whole scene was roughly as much a turn on as seeing your parents have sex.
So I'm actually somewhat enjoying seeing Ayane getting broken. Such an annoying character.