In the year 20XX, a deadly sperm virus pandemic breaks out all over the world. While researching treatment methods, evidence is released worldwide that the vaginal fluid of a certain number of women contains a specific medicine. It is then proven that if a woman with the vaginal fluid containing the therapeutic ingredients reproduces and the man empties his sperm while feeling ecstasy, he will be cured. Currently, there are signs of the virus being eradicated all over the world, and in Japan, the remaining three severely ill old man patients are being treated while hospitalized in an isolation facility. However, one day, when the virus is resisting strongly and treatment is difficult, a savior appears: Kokoro. She is still a teenage girl... but after being tested, she receives a notice from the government that she is a woman with a unique constitution who has a cure. After consulting with her mother, she makes up her mind and goes to the facility for training. Even during this training, she finds out that she is a pussy that secretes vaginal fluid with super-strong antibodies. She somehow manages to hold down the creepy old man patient who is raging as a sex-crazed ghost with no self-control due to a seizure, and ejaculates with her pussy juice and pile-driving piston. Even when her face is licked all over and she is covered in foul-smelling semen, Kokoro cures one patient after another who is into intense sex with old men. Can she really save this country... this world with her pussy? This is the story of a brave and chosen girl.