Oresama Teacher , Vol. 19 — Izumi Tsubaki

Mafuyu is the no-nonsense, take-charge and hard-hitting leader of her high school gang. But when she gets expelled for being a delinquent, her mother, fed up with her daughter's wayward ways, sends Mafuyu to an isolated school far off in the country.

Hayasaka is losing his memories! It's a stressful situation, but he doesn't really remember his friends in the Public Morals Club, so he doesn't have anyone to turn to for help. When he gets suspended for fighting, he decides there's no reason to go back to Midorigaoka. But Mafuyu and Yui aren't going to give up on their friend, even if they have to travel deep into the mountains to a house full of dark secrets to find him!