Fukami is the son of a former gangster who works as a high school janitor. He’s also working for his uncle Majima Yoshiki, watching over his cousin Yui. When a conflict erupts between the rival gang, turning the school into a battlefield, Yoshiki winds up dead. Now Yui is being targeted by underhanded men trying to kill her. While the school is in lockdown, Fukami casts aside his work in order to save Yui.