Muscular mother fighting for her son

``I'm quitting school today.'' Mizuki, who works as a physical education teacher at the school her son Gaku attends, was standing at the podium for the last time. The reason why Mizuki decided to retire was because of the mean bullying towards Manabu. In place of her son, who is unable to bear the bullying that gets worse day by day and attempts to take his own life, a mother quits school and stands up to take revenge on her classmates. Using her trained muscles, Mizuki finally locates the students' hangout and sneaks in, regardless of the danger...