Oresama teacher, vol. 15 (Viz Media)

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. Mafuyu is really happy to be a normal student going on a normal school trip. In her delinquent past, school trips were all about beating up on delinquent from other school, so she's excited at the chance to relax and enjoy the activities. But it turns out her old rival from West High are in the same town on their school trip! Will Sakurada ruin her cherished taste of normalcy?!