A middle-aged couple, relatives who are taking care of a niece who came to Tokyo for school. The uncle's desires awaken when a young woman enters the household. The niece gets excited and masturbates while watching her uncle have sex with his wife. Noticing the niece's sexual frustration, the uncle starts pursuing her in secret. He enjoys her plump young body. The wife, realizing this, cannot forgive her lecherous daughter and has her taken by a young man.
