An eighteen-year-old girl named Fuuko Izumo is cursed with a power she calls Unluck, which inflicts devastating misfortune on anyone who touches her skin. After a lifetime of isolation and loss, she is prepared to end her own life when she is suddenly interrupted by a strange, lecherous man who seems completely unaffected by her ability. He is Andy, an immortal being whose power, Undead, allows him to regenerate from any wound, making him impossible to kill. For Andy, who has grown weary of eternity, Fuuko’s catastrophic touch is not a danger but the ultimate opportunity. He decides to use her power to finally achieve the greatest death imaginable.

Their unusual partnership quickly attracts the attention of a shadowy organization called the Union. This group is composed of individuals like them, known as Negators, who have the ability to negate specific rules of the world. The Union’s mission is to manage quests given to them by a sentient, brutal book named Apocalypse. These quests involve capturing or neutralizing UMAs, conceptual monsters that embody natural phenomena or abstract rules, from Spoil and Burn to Autumn and Galaxy. Failure to complete these quests in time results in the addition of new, harmful UMAs to the world, and one hundred failures will trigger Ragnarok, the end of the world.

After a violent initial confrontation, Andy and Fuuko are forced to join the Union, where they meet a diverse cast of powerful Negators. Among them are Shen, a boisterous Chinese martial artist with the power of Untruth which reverses intentions; Gina, an elderly woman who uses Unchange to freeze objects in their current state; Juiz, the ancient and stoic leader of the Union whose ability Unjustice forces others to act against their own sense of justice; and Billy, a charismatic gunslinger whose mysterious power remains hidden. The series follows Andy and Fuuko as they undertake dangerous missions, growing closer and learning to combine their abilities in creative ways—such as when Fuuko charges bullets with her Unluck to be fired by Andy’s regenerating fingers.

As they delve deeper into the Union’s secrets, the story expands beyond simple monster-of-the-week encounters. The Autumn Arc introduces Akira Kuno, a manga author whose power, Unknown, causes him to be forgotten by the world. He possesses a prophetic book revealing that the world is stuck in a time loop. The series shifts dramatically as Andy and Fuuko learn that Juiz and Victor, Andy’s original, ruthless personality, have lived for billions of years, using an artifact called the Ark to reset the world after each Ragnarok in a desperate attempt to finally defeat God. This revelation coincides with the emergence of Under, a rival organization of Negators led by the traitorous Billy, who have their own plan for reaching the next loop.

The narrative escalates into the Ragnarok Arc, where Fuuko is assassinated, forcing Andy on a desperate journey through the underworld to recover her soul from a UMA named Ghost. Upon her revival, Fuuko resolves to end the cycle of tragedy by creating a perfect Union in the next world. Taking Juiz’s place, she uses her knowledge of the past loops to travel the globe and recruit future Negators before their powers awaken, preventing the accidents that made their lives miserable. This begins the second major saga, where the story transitions from survival to a proactive, long-term plan to change fate and liberate the world from God’s cruel game once and for all.