@JesusInStripeZ While I agree with you on Hinohara liking Nagai (and Nagai liking her), I 100% disagree on any grooming accusations, at least so far. She has been doing her hardest not to do anything extra, apart from what she needed to do to keep a delinquent interested in something very anti-delinquent like singing lessons. It's not as easy as trying to teach a regular, obedient student who's already interested in singing. She has got what it takes, though. Perhaps it's tragic she likes him, but saying it's grooming and predatory is nonsense. At least so far. She's not guilty of anything until she is guilty of something.
Nagai falling for her is perfectly natural. She's the only person in the world who pays attention to him and thinks he can become something in life. Seeing how she's a pretty funny and nice personality, relatively young and very attractive, it would be strange if he didn't fall for her.
I've said it before, but I find it kind of funny that there would be a million people in Japan alone who would want to save (someone like) Nagai from (someone like) Hinohara's clutches, but once "saved", they wouldn't give a single shit about what happens to Nagai afterwards. Without Hinohara, he would go back to being nothing but a delinquent. The teachers would either ignore him or berate him, calling him a failure. That's it. The million people would feel very proud of themselves, though. What I like about fiction is that I can just enjoy the story, without caring about how it would be a lose-lose situation in RL.