On a certain day nearing the end of the Showa era, Mika had opened a page titled "Showa Sex Crimes." Her husband had run a factory manufacturing pistons as a subcontractor for an automobile company. As the 1970s drew to a close, he suddenly died of a heart attack. The factory employed 78 workers, and Mika took responsibility, deciding to shut it down. Five years after the factory's closure, Mika and her sister Reiko lived together in the residential section of the former plant with Mika's husband's brother and his wife. However, the end of their peaceful life was approaching—.