Matsuzaka Sato is a high school girl, and she lives in an apartment with a girl named Kobe Shio. Sato believes that her favorite person in the world is Shio, and for Shio, Sato works hard to earn money outside of school to support herself and Shio. While working, Sato meets a female store manager who seems kind but has a strong possessiveness and deducts wages, a married teacher who has unrealistic thoughts about her, etc. However, Matsuzaka Sato is not a silent lamb. Facing the cruelty of society, she responds in a more cruel and cold way, just to be with Shio forever. And there are missing person notices posted everywhere on the street looking for Kobe Shio, and there is also a terrifying room in Sato's house with three bags...