Dude... I knew that Mizutani was a nut-job the way she was thinking moving into Kataoka's apartment while still paying her apartment's rent would somehow make it easier on her financially, and that it would better her precarious position in a situation where if the school found out she had let two of her students - boy and a girl - live together would see her fired, when all doing that would do is make it even worse for her if the school found out.
But now she's even raping her own student whom she's freeloaded off of, just so she can continue freeloading off of him and Yuki's cooking, all the while seemingly doing her best to keep trying to convince Kataoka that his relationship with Oozura won't work out.
Mizutani is in some deep shit, so much more so than before she moved into with Kataoka.