Spontaneous Human Combustion: a chaotic phenomenon that has plagued humanity for years, randomly transforming ordinary people into flaming, violent creatures known as Infernals. While Infernals make up the first-generation accounts of Human Combustion, the second and third generations became known as pyrokinetics—people gifted with the ability to manipulate and control their flames while remaining human. To combat the Infernal threat and discover the cause, the Tokyo Armed Forces, Fire Defense Agency, and Holy Church of Sol produced their answer: the Special Fire Force. Young and eager third-generation pyrokinetic Shinra Kusakabe, nicknamed Devil's Footprints for his explosive ability to ignite his feet at will, becomes a member of the lively Special Fire Force Company 8. Upholding the brigade's duty to extinguish the blazing Infernals and lay their souls to rest, Shinra is determined to become a hero who will save the lives of those threatened by the flame terror. However, this is not the hero's game Shinra imagined. The Fire Force is a fractured mess of feuding brigades, abnormal Infernal sightings are increasing all over Tokyo, and a shadowy group is claiming to have answers to the strange fire that caused the death of Shinra's family 12 years ago. Faced with many obstacles within and outside the Fire Force, Shinra fights to uncover the truth behind the burning mysteries that have kept him in the dark.

After his confrontation in the Nether with his younger brother Shou, Shinra Kusakabe's resolve to become a hero that saves lives from the flame terror strengthens. Finding a way to turn the Infernals back into people, unraveling the mystery of the Evangelist and Adolla Burst, and saving his mother and Shou—these are the goals Shinra has in mind. However, he has come to realize that attaining these goals will not be easy, especially with the imminent danger the Evangelist poses. The Evangelist's plan is clear: to gather the eight pillars—the individuals who possess Adolla Burst—and sacrifice them to recreate the Great Cataclysm from 250 years ago. Having been revealed by the First Pillar that the birth of a new pillar is approaching, Shinra is determined to protect his fellow pillars from the Evangelist. Thus, the fiery battle between the Special Fire Force and the Evangelist ignites. Together with the Special Fire Force, Shinra's fight continues as he uncovers the truth about the Great Cataclysm and the nature of Adolla Bursts, as well as the mysteries behind human combustion.

The story is set on Okinawa's isolated island of Iwado, which has seen a growing movement advocating a return to an autonomous government. Ao Fukai, a 12-year-old boy with a missing father, lives on the island with an old doctor named Toshio and is about to enter middle school. Ao's mother was taken away a decade ago by unknown individuals. Naru Arata, Ao's 12-year-old childhood friend and the story's heroine, lives with her father, older sister, and grandmother. She has a Yuta power awakened within her due to an incident when she was young. A mysterious entity called Secret suddenly appears and launches an attack on the Scub Coral lifeform on the island. Ao launches a certain military FP called Nirvash aboard a Japanese military transport in his fervent desire to protect the island. (Source: FUNimation)

In the backwater town of Bellforest lives a 14-year-old boy named Renton Thurston. He desires to leave his home behind and join the mercenary group known as Gekkostate, hoping to find some adventure to brighten up his mundane life. However, stuck between his grandfather's insistence to become a mechanic like him and the pressure of his deceased father's legacy, the only excitement Renton finds is in his pastime of riding the Trapar wave particles that are dispersed throughout the air, an activity akin to surfing. Everything changes when an unknown object crashes through Renton's garage, discovered to be a Light Finding Operation—a robot capable of riding the Trapar waves—specifically known as the Nirvash typeZERO. Its pilot is a young girl named Eureka, a member of the Gekkostate, who requests a tune-up for the Nirvash. Their meeting sparks the beginning of Renton's involvement with the Gekkostate as he takes off alongside Eureka as the co-pilot of the Nirvash.