A father-in-law falls in love with his son's wife, Ayaka, whom he should never be interested in. He observes Ayaka's private life and fantasizes about her. He also peeks at her having sex with her son and masturbating. One day, as he peeks at his son masturbating, Ayaka calls out to Ayaka... "Dad, I knew you were peeking at me." However, instead of getting angry, Ayaka invites him...