Married woman Aya works as a teacher at the same school as her husband. Kind and diligent, she is adored by her students, but her husband's outdated teaching methods have made him disliked among them. This growing rift between the couple comes to light one afternoon when Aya's husband witnesses student Kimura bullying Okamoto. Unable to tolerate Kimura's disrespectful attitude, he strikes him. When Aya tries to calm the situation, Kimura remains furious and later calls her to a private meeting. He threatens to report the assault unless she exposes her breasts to him, setting off a chain of events that will drastically change Aya's life.