Japan Men’s Sports College, commonly known as J-Balls, includes an organization that aims to cultivate healthy sperm to fight declining birth rates. Each year, it selects the top student and awards him the prestigious title of Best Balls. The recipient becomes the most desired donor at sperm banks and is given a solid gold ball worth millions, meaning this award is a gateway for young men looking to make a quick buck. Kiminari hopes to be this year’s Best Balls, so when Akira, who failed the J-Balls entrance exam, asks him out, Kiminari agrees on the condition that Akira help strengthen Kiminari’s reproductive ability. Both young men are insatiable and find they can’t keep their hands off each other. But, they’ve enjoyed themselves so much that Kiminari’s sperm count has gone down! Is love dangerous for a Best Balls candidate?