Teacher couple Fuji Kanna and her husband live a peaceful life together. The husband, striving to maintain good relationships with his students, one day catches a student named Iizuka extorting money from a classmate. When Iizuka denies it, the husband flies into a rage and physically strikes him. Kanna rushes to intervene, but it's too late—she feels a deep unease about her husband's actions. The next day, hoping to avoid a major incident, Kanna secretly tries to apologize to Iizuka without her husband finding out. But Iizuka, furious over the corporal punishment, refuses to forgive her and instead demands she undress. In an instant, the couple's ordinary life is shattered, spiraling into an irreversible descent.