Minamoto-kun's facial features are so striking that they make people think he is a girl. This led to bullying from jealous girls during middle school, causing him to develop a fear of women. As a result, he attended high school for boys and now, as he enters college, he has made a vow to overcome his past trauma. However, just when he was starting to heal, his father remarried and asked him to leave the house. His aunt, who is an attractive non-tenured professor at his college, welcomed him into her apartment. Upon arrival, she showed him her breasts and revealed that he would be her "guinea pig" in a reverse Hikaru Genji project.