Yua Mikami is a girl who is engaged and currently living with her future husband. One day, she went to a class reunion with her high school friends. There, she met her old love from three years ago, who is now a successful businessman. She was coerced by her old boyfriend into a sexual encounter. In the days that followed, he always found ways to approach her. Although she was cheating, her fiancé was still unaware and continued to have feelings for her. Until one day, he decided to propose and received a letter from her lover...