The dream of Sayaba is to be alone, and the dream of the system is to be raised as a brave person. In short, it's the story of a girl who is oppressed by the system in the post-apocalyptic world, who keeps on being a mother of God, who keeps on making death, and whose goal is to become a brave man to save the world (fog). There is a carry-on space, a trading system, attribute points, and a zombie apocalypse.