Kisaragi Asuma, a passionate young man with a strong sense of justice, constantly trains himself, striving daily to become the manliest man. Being kind to the weak and rescuing bullied kids harassed by delinquents was simply second nature to him. One day, he was asked to help test the effects of a fatigue recovery supplement allegedly created by the science club. The supplement's effects are immediate and Asuma is delighted with how light his body feels. However, gradual changes are occurring within his body. The supplement's effects shift his hormone balance transforming him into a woman's. But that's not all. He found himself aroused by male body odor, developed a physique that felt pleasure through his anus and was overwhelmed by surging sexual desire. Not only has his appearance changed but his inner self has become like a woman seeking a man. Though bewildered by his body's changes, he tried to urge self-control, thinking he couldn't indulge in pleasure while aiming to be the manliest man. He tries to control himself but he finds himself increasingly addicted to masturbation. During these days, Asuma accidentally catches a glimpse of the penis of the bullied kid he'd always helped. It was so impressive that it was hard to believe he was a bullied child and to him at the time, it seemed so attractive that he found it difficult to control his own impulses.