Chisato lives with her husband and stepson. One day, her sister Shinobu arrives with her son. Each hiding their family circumstances, they start living together. One day, Shinobu witnesses her sister having an indecent relationship with the stepson. The emotion that surges in Shinobu's heart is jealousy towards her sister's sex life. From that day on, Shinobu's days become filled with masturbation. Then, the mother, frustrated with unmet desires, ends up having a relationship with her son. Jealousy swirls between sisters and parent-child relationships. The complex web of sexual relations becomes increasingly tangled...
