Oresama Teacher is mostly about the trials and tribulations of Mafuyu Kurosaki, reformed (?) delinquent who just wants to be a normal high schooler with normal high school experience and how that dream never ever happen because she is a brawler to her core. But it is also about the fight for the soul of her new school, Midorigaoka Academy. Her homeroom teacher (and childhood frenemy) Takaomi Saeki is the grandson of the founder of the school, and he has a bet with the current school president--winner takes all. Takaomi has a weird but reliable ally in Mafuyu, but a new adversary has just joined the student body, and she might be more than any of them can handle!

Toko Hanabusa is the younger sister of ex-student body president Miyabi Hanabusa. While Miyabi used his dazzling powers for convoluted good, his sister seems to be made of darker stuff. Her first week in school, she manages to get Takaomi to (temporarily?) remove himself from the game. Now Mafuyu and the Public Morals Club are the only thing standing between Midorigaoka and this formidable new foe.

And while Mafuyu and her friends are certainly enthusiastic, they aren't known for their strategic skills. How are they going to protect their school and themselves?!