She soon meets an "undead" man who has amazing regenerative abilities and who desires to die the best death possible, disliking his immortal life.

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 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 (like 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.

Produced and planned by TMS Entertainment,[a] and animated by David Production, it was directed by Yuki Yase, with character designs handled by Hideyuki Morioka, and music composed by Kenichiro Suehiro.

[19][20] The series aired in two consecutive cours from October 7, 2023, to March 23, 2024, on the Super Animeism programming block on all JNN affiliates, including MBS and TBS.

[23] The series is streaming on Hulu in the United States,[3][24] and worldwide outside Japan on Disney+ (Latin America on Star+, India and Southeast Asian territories on Disney+ Hotstar).

[37][38] Anime News Network commended Tozuka's artwork but was highly critical of the depiction of Andy and Fuuko's relationship and its sexually exploitative nature.

[37] Hannah Collins of Comic Book Resources praised Tozuka's art in depicting violence and its comedic potential but also criticized the series' portrayal of the main characters' relationship wherein "Fuuko's body is primarily used as a sexualized tool for Andy to grope and fling around at will.