Undead Unluck

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 is tormented by the fact that her "unluck" ability brings bad luck to anyone she directly comes into contact with. 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.
Eventually, an assassin of the Union called Shen tells them that the organization has a special team consisting of ten people with special abilities, and that by joining the team, they will no longer be hunted, so the two decide to join in order to attain Andy's wish for "the best death", and face numerous enemies and the mysteries of the world.
The missions of the team are proposed by a talking book called Apocalypse (黙示録（アポカリプス）, Apokaripusu), which has supernatural powers. There are people with the ability to negate the rules of the world called Negators (否定者, Hitei-sha). The Union is an organization of Negators specialized in the hunting of UMA (ユーマ, Yūma) or Unidentified Mysterious Animals, creatures that are the embodiment of the Earth's rules (such as thirst and decay) and are created by God as both the objectives for the quests provided by Apocalypse, as well as punishment for failing them. They also must defeat a group of Negators that opposes the Union called Under (アンダー, Andā) and Regulators (調整者, Regyurētā), beings chosen to do God's bidding.