Shiritsu Ajikari Gakuen

A man's sister runs a restaurant that is targeted by a group of men who eat without paying. The man confronts them with a knife, and during the fight, an older man intervenes by throwing a beer can, causing the attackers to fall and flee. The older man introduces himself as a principal from a school and challenges the man to a knife duel. The fight is a test of speed in peeling an apple. The man loses and is required to attend the school. His background with food becomes relevant as he begins his time there.