- Acceptable Targets: Organized religion does not get a good portrayal in Fire Force. The followers of the Evangelist are fundamentalists who want nothing more than the destruction of the entire world, and the Church of the Holy Sol is a shady organization that is ultimately hand in hand with the Evangelist. The morally failing, corrupt church is placed in stark contrast to the religious characters who are sincere in their beliefs, showing that the main moral of the series is "It doesn't matter who or what you have faith in, so long as you use it to do the right thing instead of blindly following orders".
- Americans Hate Tingle: Tamaki was ranked second in the first popularity poll in Japan. However, she's more divisive overseas due to her "Lucky Lecher Lure" curse, since many Western fans take issue with her entire character being a walking Fanservice machine who loses her clothes and/or gets groped in almost every appearance. As a result, a lot of Western fans find her to be a rather one-note character.
- Awesome Music: The first opening theme, "Inferno" by Mrs. GREEN APPLE, is an exciting yet slightly melancholic rock piece. It's followed up by MAYDAY, from Coldrain, featuring Ryo from Crystal Lake. A hard rock and death metal piece that shakes you to your core.
- Badass Decay: Assault got hit with this almost instantly. Even though he was introduced as the member of the White Clad who could take on all of Company 8 at once and win, he gets knocked out cold by Iris of all people, and from that point onwards becomes an outright Joke Character who's infatuated with Tamaki and tries to win her love.
- Base-Breaking Character: Tamaki. One part of the fandom likes her and enjoys her Tsundere moments, her Ship Tease with Shinra, as well as the Fanservice she provides, while the other considers her to be an one-dimensional character whose only purpose in the story is to be a walking fanservice object. Not helped by the fact that Maki, who also has her fanservice moments, is more badass than her.
- Better on DVD: The Company 5 arc flows faster and smoother when reading at once.
- Broken Base: Tamaki's "Lucky Lecher Lure" curse. Some find it amusing, especially given the improbable situations she can end up in. Others, however, consider it to be unnecessary fanservice that turns her into an one-dimensional character.
- Captain Obvious Reveal: The second it was mentioned that Shinra's little brother Sho's body wasn't found in the first episode, viewers immediately figured out that he was still alive and that he was going to be an antagonist. The fact that Sho had white hair made it even more obvious for two reasons: 1. White Hair, Black Heart being a common villain trope in anime. 2. It's such a distinct look for an infant who supposedly died to have.
- Critical Research Failure: Faerie's Adolla Burst explanation is cited by some readers as one of the worst misunderstandings on gravity. He explained that in order to reduce Earth's gravitational pull toward an object he increased the object's mass closer to that of Earth while Newton's Law of Gravitation states that gravitational force between two objects is directly proportional to said two objects's masses, thus what he should've done is reducing the object's mass. Even if the explanation turns out to be true in real life, Faerie seemingly phasing through Sho's sword slash is not something that should happen to something with mass and density close to Earth's.
- Ensemble Dark Horse: Shinmon Benimaru is extremely popular, for his appearance and for being one of the most badass characters in the series.
- Fan-Preferred Couple: There are fans who like to ship Iris and Hibana together due to the history that they share, preferring to see their relationship as that of lovers instead of surrogate sisters.
- Fetish Retardant: The amount of fanservice has been a regular criticism of the series, especially since much of it tends to happen at inappropriate times and causes severe Mood Whiplash as a result. Tamaki and her "Lucky Lecher Lure" curse is the main source of fanservice, and the laws of the universe seem to dictate that, through no one's fault, she will end up losing clothes, getting groped, or being sexualized in some manner. That's bog standard enough for shonen manga, but it's not only a gag that's run into the ground, it's also half-hearted. It feels more like Atsushi Okubo is paying lip service to the fact that boobs and "ecchi"-style slapstick is indivisible from shonen manga these days.
- Growing the Beard: Most fans will agree that the series really starts to pick up after the Evangelist and White Clad are introduced.
- Harsher in Hindsight: The anime premiered mere weeks before Kyoto Animation's Studio 1 building was burned to the ground by an insane arsonist, killing 36 people in Japan's deadliest mass murder to date. The plot of the third episode, meant to air the following day, involves an arsonist trying to burn down a building and kill the people inside. Naturally, it was postponed until the following week, with the color of the flames also being changed for good measure.
- Ho Yay:
- Both Iris and Hibana are quick to praise the physical beauty of Maki, with Hibana doing so in the shower, including Maki blushing and rhetorically asking if Hibana means it. Hibana and Iris also have moments of this including Hibana doing a groping moment with Iris in the shower.
- Benimaru and Konro due to how protective and loyal they are to each other.
- Shinra and Arthur. Despite their Volleying Insults, the two can still be oddly close to each other. Most notably, when they are trying to sleep (they sleep in the double decker bed), they often open up to each other with little hesitance. It doesn't help that Arthur can and will get away with using Shinra as a vehicle, even if Shinra is occasionally annoyed by it.
- There is some Accidental Innuendo between Shinra and Obi. The first time they formally meet, Obi gets very close to Shinra and outright calls him adorable. Later on, when Hibana shows to have little trouble getting Shinra and and the rest of Company 8 on her side, she and Obi start a comedic exchange that out of context look like they were competing for Shinra via Through His Stomach.
- Hinawa had a tragic dynamic with Tōjō, his comrade from his military days. Failing to give Tōjō a satisfactory death (using a baptized gun) after he turned into an Infernal still haunts Hinawa. During his battle with Arrow, just seeing an illusion of Tōjō (made by Mirage in an attempt to demoralize him) fills Hinawa with the needed hope and peace to finish the battle victoriously.
- LGBT Fanbase: The male cast of the story quickly got a gay male following, especially Obi, for his Workout Fanservice nature, and Vulcan, for his Hot Men at Work presentation.
- Lost in Medias Res: The first two arcs move really quickly, giving the sense that major plot moments are simply happening without the proper build-up or establishing of a current Status Quo. For example, Infernals were introduced as people who are mindless shells of their former selves in the first episode... only for the idea of Infernals capable of conscious thought to be quickly introduced in the second episode. Before the audience can begin to digest that knowledge, they're hit by the appearance of a fully cognizant one in episode four.
- Memetic Mutation: "Látom" is used frequently in-universe at the ending of a prayer akin to "Amen". In some comedic situations, characters use it to express their condolences. The latter use of the phrase gets seen like "Press F to Pay Respects" and is used in the same manner. Some characters (like Sister Iris!) use it as a Pre-Asskicking One-Liner.
- Moe: Sister Iris is adorable. A kind-hearted girl with Hair of Gold, Heart of Gold and Innocent Blue Eyes who prays for the souls of Infernals to find peace, it is no wonder that both characters and fans become protective of her.
- Paranoia Fuel: The entire premise: you, a loved one, or a relative could, at any time, suddenly turn into an Infernal, a horrifying monster that constantly feels the pain of burning to death and destroys everything in its path. Once this happens, the only thing that can be done for you is to be put down by the Special Fire Force. Anyone could transform, and there's no telling when it will happen.
- Visual Effects of Awesome: The animation team is comprised heavily of animators who left Studio Shaft in 2018 due to poor management, a studio well-known for its beautiful, visually distinctive anime. Unsurprisingly then, the visuals are easily the most praised aspect of the anime, both for the animation and excellent direction.
YMMV / Fire Force