Still haunted by the trauma of her school days, Nagisa was hesitant to date men, but finally her boyfriend proposed to her and she was feeling happy. Then, one day, when she went to his family's house for the first time to say hello... Nagisa was frozen when she saw the face of his father, who lived in a single-parent household. The father was the principal who had taken Nagisa's virginity when she was in high school. Nagisa lamented her fate, but her father handed her the vibrator he had used that time and ordered her to "use this when you have sex with your son tonight."