@PickYerPoison lol, I have long since stopped caring when it comes to manga, almost all of it is aimed at teen agers to young adults, at least what we get translated, the young attractive teacher barely even registers as a creepy flag anymore unless the author is trying to raise those flags, and when they want to they can do that quite easily.
I look at it this way, aoc in most of the world either doesn't exist, or in more developed areas 14-16, there are a few pockets where its younger, one state in america has it at 13 but I haven't looked, and I think a european country is also that low. now you can look into the power dynamic of this person technically has more power over someone else so it can't be consensual, but the moment you start thinking that way you may as well take it to the logical extreme of there is no way to have penetrative sex without it being rape. The way I see it is this
1) is the author portraying it as creepy or are you putting your own feelings on it?
no
2) is the author portraying it as someone is taking advantage of the other?
no
3) are any of the characters at an age where this shouldn't even be a topic (you know, the actual definition of pedo)?
no
Then I see no real problem, a lot of issue like this come up with, the kobayashi example, an extreme difference in cultural norms. I'll give its creepy when consent is in question, but I also have a problem with refusing to allow someone else's agency. Had a friend in highschool where he dated a girl a year younger than him, this put them on that she is under aoc and he is aoc, apparently they had sex, and she was... well let's put it this way, after the mask fell he wanted the hell away from her, and she decided to hold statutory over his head for 3 years, even talking to a cop we can trust about it, they more or less said even if she was at aoc, it means nothing if the parents get involved, and she was everything if he left her. thankfully he is ok, and nothing happened when he went off to 'collage' and she dropped it after a month or so, but its the fact I know multiple people who got trapped this way (3rd hand knowledge, this was the one I watched 'up close' and knew the shit as it happened) that I see things this way. the only way this changes is if a character is forced to do something or agency is taken away.
The creepy element here comes almost exclusively from the girl showing some yandere tendencies.