Year 198 of the Solar Era in Tokyo, special fire brigades are fighting against a phenomenon called spontaneous human combustion where humans beings are turned into living infernos called "Infernals". While the Infernals are first generation cases of spontaneous human combustion, later generations possess the ability to manipulate flames while retaining human form. Shinra Kusakabe, a youth who gained the nickname Devil's Footprints for his ability to ignite his feet at will, joins the Special Fire Force Company 8 which composes of other flames users as they work to extinguish any Infernals they encounter. As a faction that is creating Infernals appears, Shira begins to uncover the truth behind a mysterious fire that caused the death of his family twelve years ago.
On his first day with Special Fire Force Company 8, Shinra Kusakabe, a third-generation pyrokinetic who is able to produces flames from his feet, meets his fellow company members and begins to fulfil his wish of becoming a hero.
Arthur Boyle, the self-professed "Knight King," arrives at Company 8, and immediately, there are tensions between him and Shinra. With the Rookie Games coming up, Hinawa wants to see what the two new recruits are really capable of.
Shinra and Arthur compete in the Rookie Fire Soldier Games, a contest to test the abilities of each year's newest recruits. However, they are interrupted at the goal by the mysterious man who created explosions at their last fire scene.
A call mistakenly comes in to Company 8 to rescue a dog out of a tree, to which Shinra and Arthur respond. However, when an Infernal suddenly appears at the district courthouse, the two must play catch-up to join the rest of the company.
While jogging, Shinra inadvertently disturbs Iris's purification rite, and sees that she is troubled. When Iris later turns up missing, the other members of Company 8 rally to Company 5's compound, to which Iris had secretly slipped away.
Shinra confronts Hibana in an attempt to rescue Iris, and must once again deal with her ability to make his body shut down. The story of Hibana and Iris's youth as orphans, as well as Hibana's rise to prominence, is revealed.
The members of Company 5 and 8 get together for a cookout, ostensibly to celebrate a successful nighttime training exercise. Using the bylaws of the Special Fire Force, Obi gets Shinra and Arthur temporarily assigned to the 1st to investigate it.
Obi goes over Hibana's research, and learns that the artificially-created Infernals she dissected all had traces of insect DNA in them. Shinra and Arthur's investigation at the 1st continues, and they finally get their first lead on a culprit.
Tamaki watches on as Shinra confronts Rekka over his actions, and reminisces about how she once looked up to the lieutenant. Rekka reveals his objective in seeking out compatible children, one which could spell disaster for the entire world.
A captains' conference is convened to allow the Special Fire Force to discuss the situation with the Evangelist and the White-Clad. Shinra once again has an encounter with Joker, in which startling information about Shinra's brother is revealed.
While Company 8 searches for clues about the Evangelist, Hinawa recounts the tale of how the company originally came into existence. A lead prompts the crew to pay a visit to Company 7's jurisdiction in Asakusa, and its captain, Benimaru.
Company 8 pitches in to help rebuild Asakusa after the latest Infernal incident, helping to gain the trust of its people. However, a White-Clad plot threatens to undo all of their goodwill, prompting Obi to take matters into his own hands.