The anime's story is set in a town in a not-so-ordinary countryside, where a big and strange occurrence is happening to its residents. But a young girl named Shizuru Chikura has a strong desire to see her lost friend again. Shizuru and three other girls board an abandoned train, and they set out to the outside world, where survival is not certain. What awaits them at the last stop of the "Doomsday Train?