Fuuko Izumo is an 18-year-old girl who has been living in seclusion for ten years since an incident that left more than 200 people dead; including her parents, when she was eight years old. Following the completion of her favorite long-running shōjo manga series, Fuuko decides to commit suicide. She soon meets an “undead” man who has amazing regenerative abilities and who desires to die the best death possible; disliking his immortal life. For the sake of convenience, Fuuko names him Andy because he is undead, and they begin to work together. However, they soon see themselves chased by the Union (ユニオン, Yunion), a mysterious organization.