In a fictional pandemic, researchers discover that certain women's vaginal fluids can cure a deadly sperm virus if infected men have sex and ejaculate completely. Kokoro, an adult heroine portrayed as a young woman in this role-play, is identified as having exceptionally powerful antibodies and volunteers after consulting her mother. At a treatment facility she restrains three older patients driven wild by the disease, rides and pounds them until they empty themselves, and continues treating them despite being licked and covered in foul-smelling semen. Her mission is to cure every patient and save both the country and the world.