"Fire Force" is set in a world where spontaneous human combustion turns people into flame-wielding creatures known as Infernals. The phenomenon, referred to as the Great Cataclysm, has plunged society into chaos, leading to the formation of the Special Fire Force, a group of pyrokinetic individuals tasked with combating Infernals and investigating the cause of the combustion incidents. The story primarily unfolds in Tokyo, where various Fire Force companies operate under different ideologies and goals.

Shinra Kusakabe, the protagonist, is a Third Generation pyrokinetic who can ignite his feet to achieve superhuman speed, earning him the nickname "Devil's Footprints." He joins Special Fire Force Company 8, a unit dedicated to uncovering the truth behind the Infernal outbreaks while maintaining a balance between the other Fire Force companies. Shinra’s personal motivation stems from a tragic childhood incident where his family died in a fire, and he was falsely accused of causing it. His younger brother, Sho Kusakabe, was believed to have perished in the same event but later resurfaces as a key antagonist aligned with the Evangelist, a shadowy organization orchestrating the combustion phenomena.

The narrative explores the conflict between the Fire Force companies and the Evangelist, who seek to trigger a second Great Cataclysm to reshape the world. The Evangelist’s followers, known as the White-Clad, manipulate events to create Adolla Bursts, individuals with immense pyrokinetic power tied to the Adolla Realm, a mysterious dimension that serves as the source of all flames. Shinra and Sho are both revealed to be Adolla Bursts, making them central to the Evangelist’s plans.

Key characters include Arthur Boyle, Shinra’s rival and fellow Company 8 member, who wields a plasma sword and harbors delusions of being a knight; Maki Oze, a Second Generation pyrokinetic who manipulates flames externally; and Captain Akitaru Obi, the non-pyrokinetic leader of Company 8, who provides strategic guidance and moral support. Other Fire Force companies, such as Company 1 led by Leonard Burns and Company 4 under Karim Flam, play significant roles in the overarching conflict, each with distinct philosophies and approaches to handling the Infernal crisis.

The story delves into themes of faith, science, and the nature of humanity, as characters grapple with their roles in a world teetering on the brink of destruction. The Fire Force’s investigations uncover deeper conspiracies involving the Tokyo Empire’s government, the Holy Sol Temple, and the origins of pyrokinetic abilities. As the plot progresses, Shinra and his allies confront increasingly powerful adversaries, including the Evangelist’s elite enforcers and the enigmatic Haijima Industries, which conducts unethical experiments on pyrokinetics.

The narrative builds toward a climactic confrontation between the Fire Force and the Evangelist, with Shinra striving to prevent the second Great Cataclysm while reconciling with his brother. The series balances intense action sequences with moments of character development, exploring the personal struggles and motivations of its cast. Through its intricate world-building and layered plot, "Fire Force" presents a compelling exploration of a society on the edge of collapse and the individuals fighting to save it.