Yasuyo and Mariya are a couple of biology students. One day, Mariya falls victim to an unforeseen accident! From that day on, Yasuyo immerses himself in research to revive his lover. In the end he succeeds... but Mariya falls for the first man he sees, Yasuyo's brother Ukyo! What's more, his body will fall apart without regular semen injections! Seeing his lover prostate, filled with the seed of another man, what will Yasuyo do!?