Kiyozuka Nana and her brother work together at the Kyuujin Dental Clinic. Since they always wear masks at work, she thought her involvement in adult videos would never be discovered, so she agreed to appear in one casually. However, one day, suspicion arises that she might be in an AV, and the clinic's director confronts her. Unable to withstand pressure, Nana admits the truth, and the director takes advantage of her vulnerability to sexually harass her. The director then reports the incident to the clinic's owner. The owner calls Nana in, delivering a so-called "disciplinary warning," while simultaneously demanding a physical relationship, making increasingly excessive and coercive demands.