The "scary" teacher is actually a new, shy, and really clumsy airhead. Due to a series of unexpected events, the MC gets to see this side of her before the rest of the students do (and I'm not just talking about her personality). With the MC's help, the teacher slowly improves how she teaches her classes, and the rest of the students start realizing she isn't as creepy as they thought—while panties are constantly being flashed, of course (since the cast basically turns into the MC and an all-female group that slowly forms a harem). It's super ecchi. There are boobs and panties in literally every chapter, reachingabsurd extremes that I won't even bother describing. If you're coming into this strictly for the ecchi and zero story, this is definitely for you.

Personally, I'm dropping the manga and just waiting for an anime adaptation to come out.