"Undead Unluck" is a manga series that blends action, comedy, and supernatural elements, centering on a unique power system and a high-stakes conflict between humans and otherworldly entities. The narrative revolves around Fuuko Izumo, a young woman cursed with the ability "Unluck," which brings catastrophic misfortune to anyone who touches her. After years of isolation, Fuuko attempts to end her life but is interrupted by Andy, an immortal man with the ability "Undead," which grants him rapid regeneration and invulnerability. Andy, seeking a meaningful death, sees Fuuko's Unluck as the key to achieving his goal.

The two form an unlikely partnership, embarking on a journey to confront the Union, an organization tasked with combating the enigmatic "Negators"—individuals cursed with abilities that negate natural laws. The Union operates under the guidance of a mysterious entity known as "God," who enforces a system of rules and punishments. As Fuuko and Andy delve deeper into the Union's operations, they uncover a larger conflict involving "UMAs" (Unidentified Mysterious Animals), creatures that embody abstract concepts and threaten humanity's existence.

The story explores the dynamics between the Union's members, each possessing unique Negator abilities, and their efforts to neutralize UMAs while adhering to God's strict regulations. Fuuko and Andy's relationship evolves as they navigate the complexities of their powers and the moral dilemmas posed by their missions. The narrative introduces a rich cast of characters, including other Negators like Gina, whose ability "Unchange" prevents her from altering her appearance, and Shen, who wields "Untruth" to manipulate reality through lies.

As the plot progresses, the stakes escalate with the introduction of the "Ragnarok" event, a catastrophic scenario orchestrated by God to reset the world. Fuuko and Andy must confront their own limitations and the ethical implications of their actions while striving to protect humanity from annihilation. The series balances intense battles with moments of humor and character development, creating a compelling narrative that explores themes of fate, free will, and the human condition. The intricate power system and the interplay between characters' abilities drive the story forward, making "Undead Unluck" a distinctive addition to the supernatural action genre.