His older brother, Taro, is a problem child. His younger brother Jiro is an honor student. Yoko is a mother with two sons who grew up with completely opposite personalities. Yoko dotes on Jiro, who is about to take his exams, and ends up having a physical relationship with him. When Taro realizes the relationship between the two, his jealousy and hatred toward his mother, Yoko, grows. He threatens to tell his father about his relationship with Jiro and orders his mother to play perverted. Taro's wicked demands escalate more and more, finally leading to incest between the three father and son, including his younger brother.