Terada Aoto was a very ordinary salaryman, but he had the unusual physical characteristic of incredibly fast wound healing. One day, through his grandfather, a genetics researcher, he receives a call from a sperm bank. Long ago, Terada’s grandfather, having observed Aoto’s physical characteristics, investigated Aoto’s body… His blood, cells, and sperm were examined, revealing that besides his rapid wound healing, he possessed a gene that made him exceptionally fertile. Upon learning this, Terada develops a trauma, believing he will impregnate any woman he has sex with. The sperm bank, having learned of this, requests that he donate his sperm. Highly suspicious of this dubious offer, Terada hesitates, but ultimately accepts the job under the unreasonable conditions of only providing sperm to women under 30 years old and only through direct sexual intercourse. Then, a few days later, the request actually comes through…