Tsutomu has a strange condition where everything he eats goes straight to his penis, giving him an uncontrollable erection. Hoping to find a cure, Tsutomu visits a human lab run by Kaiyama and his assistant Musashi, who are fascinated by Tsutomu. While at a company event, Tsutomu meets Shiga, his boss's handsome son. Shiga misunderstands Tsutomu's condition and the two end up having sex. After clearing the misunderstanding, Tsutomu realizes his condition has started improving because of Shiga.
Gurume no Fukurami