Ah I see, Hizumi literally won't teach him cuz she genuinely likes him in the state he's in, which is cute in it's own way. One small issue is how's she's gonna react when he eventually gets hes shit together, cuz if his sister who's an even more girl-failure than he is can change in a month, he should be able to do a complete 180 in 3 weeks max. Only time will tell
We still have yet to understand why Hizumi's pupils are the only ones (so far) that are pitch black even when she's being kind to her mans.
Legitimately what fucked her up that badly that its now permanently stained onto her soul.