When Fuko Izumo was 8 years old, her ability "unfortunately" caused a plane accident that killed 200 people. Her parents also died in the accident, and she has been secluded for 10 years since then. In August 2020, after the long-running girl's comic that she had been following was serialized, she decided to commit suicide. At this time, she met Andy, who has the ability of "immortality". With her powerful regeneration ability, Andy can still survive even under the influence of Fuko's "unfortunate" ability. After stopping Fuko from committing suicide, the two set out to find a way to make Andy die. Later, Fuko discovered that there are other people in the world with similar abilities. People who can deny something are called "deniers", and there is also an organization called "Union" composed of deniers. The responsibility of "Union" is to complete the tasks given by the "Apocalypse", such as conquering UMA (unconfirmed organisms), etc., in order to avoid the world being added with "rules" and then leading to the end of the world.