In a world where spontaneous human combustion turns people into fiery creatures known as Infernals, the Tokyo Empire relies on specialized firefighting teams to combat this phenomenon. These teams, collectively called the Fire Force, are tasked with extinguishing Infernals, investigating the causes of combustion, and uncovering the truth behind the mysterious plague. The story centers on Shinra Kusakabe, a young third-generation pyrokinetic who joins Special Fire Force Company 8. Shinra possesses the unique ability to ignite his feet, granting him superhuman speed and earning him the nickname "Devil's Footprints." His goal is to become a hero and uncover the truth behind the fire that killed his family years ago, a tragedy that also left his younger brother, Sho, missing.

Company 8, led by Captain Akitaru Obi, is distinct from other Fire Force units due to its dual mission of firefighting and investigating corruption within the organization. The team includes a diverse cast of characters, each with their own pyrokinetic abilities and roles. Arthur Boyle, Shinra's rival and fellow recruit, wields a plasma sword and often engages in comedic banter with Shinra. Maki Oze, a second-generation pyrokinetic, uses her ability to manipulate flames to create defensive barriers. The team also includes the nun Sister Iris, who provides spiritual guidance, and her brother, the stoic and powerful Hinawa, who serves as the squad's sharpshooter.

As the series progresses, Shinra and Company 8 uncover a deeper conspiracy involving the Evangelist, a shadowy organization seeking to trigger a cataclysmic event known as the Great Cataclysm. The Evangelist's followers, known as the White-Clad, manipulate Infernals and possess advanced pyrokinetic abilities. Shinra's connection to the Evangelist becomes increasingly apparent as he learns more about his family's past and his own latent powers. His missing brother, Sho, resurfaces as a key figure within the White-Clad, brainwashed and serving as their enforcer under the alias "The First Pillar."

The narrative explores themes of faith, sacrifice, and the nature of heroism, as Shinra and his comrades confront both external threats and internal conflicts. The Fire Force itself is divided into factions with differing ideologies, leading to tension and occasional clashes between companies. The series balances intense action sequences with moments of camaraderie and humor, creating a dynamic and engaging storyline. As Shinra grows stronger and uncovers more about the Evangelist's plans, he must grapple with his own identity and the responsibility of wielding immense power in a world teetering on the brink of destruction.