The Hercules 4th planet is on the verge of death due to a strange disease that affects only men. The existence of organisms with similar genes was needed for making therapeutic drugs. At the end of a long journey in space, they finally arrive on earth. Residents of an apartment start to disappear one after another on that day. And suddenly, a mysterious young man named Suzuki appears.

Three years ago, Ayano lost her husband and was running a small delivery business on her own, raising her daughter, Asami. Unable to pay high wages and struggling with high employee turnover, she followed the advice of her neighbor, Mr. Shiroyama, and offered her body to a new employee, Nishikawa, to get him to promise to stay for three years. Then, one day, Ayano and Asami had an argument. Asami confided in her boyfriend, Tonoyama, who embraced her tenderly and suggested they live together, but afterwards, Tonoyama ran off with the company's money…