Mami, who got engaged to her office romance partner, was thought to be happily celebrating with her colleagues... However, she was tricked by her department head, Nakata, into giving him sex just once, and he even recorded it on his smartphone. Then, he threatened to show the video to her husband, and Mami was subjected to training within the company. At first, Mami resisted, but as she was repeatedly trained, she started to feel something for Nakata's sex. One day, Nakata told her, "Let me have sex with you at your home! And in front of your husband!" So, Mami invited Nakata to her house. With her husband drugged and asleep, Mami is taken by Nakata... What will happen to her relationship with her husband?