underrated. There aren't many series that succeed to be both good and ecchi. And what more, to be ecchi and homely. This is surprisingly believable as well. I'm not saying its god tire, but hell of a lot better than most mindless ecchi like to-love-ru.
And while everyone will probably agree that, for the readers/creators, our allure is morally disgusting, the actual story is not. Idr what grade they are in, but if it is near the end of elementary school (3rd-5th grade) then these types of questions should have started popping up even in more strict countries like America (where non-sealed ecchi magazines aren't in children's reach in stores... but unfiltered internet ads for them remain omnipresent)
Seriously though.... we need to get these teachers together. Such a great couple...