My mother's propensity that I knew. And that I have the same masochistic qualities... Do not peek at the SM sex of mother and father-in-law. Seeing the ecstatic expression of my mother who is tied up, Mai who is interested in bondage ends up masturbating. I was scolded and punished for peeking from my father-in-law while my mother was away. With that as a trigger, Mei's training progresses, and she falls into a rope slave.