Fire Force manga creator Atsushi Ohkubo left a comment in the 28th issue of Kodansha 's Weekly Shōnen Magazine 2019, stating: "I'm going to stop talking about the contents of my manga before they get serialized, even to people I know. I don't know where my work could be stolen from."

Although Ohkubo did not name any particular work, fans have noted that the premise of Fire Force bears a striking similarity to Trigger and XFLAG 's Promare film, which opened in Japan on May 24. Kodansha Comics publishes Fire Force in English, and it describes the story:

Terror has paralyzed the clockwork metropolis of Tokyo! Possessed by demons, people have begun to burst into flame, leading to the establishment of a special firefighting team: the Fire Force , ready to roll on a moment's notice to fight spontaneous combustion anywhere it might break out. The team is about to get a very unique addition: Shinra, a boy who possesses the unique power to run at the speed of a rocket, leaving behind the famous "devil's footprints" (and destroying his shoes in the process). Can the Fire Force discover the source of this strange phenomenon and put a stop to it? Or will the city burn to ashes first?

The plot synopsis of Promare is as follows:

30 years ago a cataclysmic event destroyed half the world in a fire, and caused a mutation that created a new race of people called Burnish. Burnish are able to create and control fire. The film centers on the members of the "Burning Rescue" fire squad, who put out fires caused by Burnish. The new rookie of Burning Rescue is Galo, a hotheaded man who wields "Matoi-Tech," named after the "matoi" banners that Edo-period firefighting units used. Galo's encounter with Lio, the leader of a Burnish terrorist group called Mad Burnish, sets the story in motion.

Director Hiroyuki Imaishi stated at AnimeJapan that pre-production on the film began in 2014. Ohkubo launched Fire Force in Weekly Shōnen Magazine in September 2015. A television anime adaptation produced by David Production will premiere on July 5. Ohkubo is best known for creating the Soul Eater manga and its spinoff Soul Eater Not! , which received anime adaptations in 2008 and 2014 respectively.