Crimson Denizens and Rinne, beings from a parallel world, seek to devour humans' precious existences. To restore the delicate balance of the world, Flame Hazes hunt these entities down. Yet such things are unknown to Yuuji Sakai, who starts his day like any other and heads to school. His day, however, takes a turn for the extraordinary when he witnesses everyone around him freeze in place and is left the only one able to move. Immediately, a Rinne begins devouring the souls of those around him, but as the creature sets its sights on Yuuji, a katana-wielding Flame Haze with blazing red hair saves him. After his protector fixes the damage done, she explains why Yuuji was able to move: he has become a Torch, a remnant of a dead human being that will eventually fade from memory. Furthermore, he is also a Mystes, a Torch that houses an unknown treasure. Before his flame burns out completely, a Crimson Denizen will try to seize the treasure he holds, so the fiery hunter decides to watch over him. As Yuuji comes to terms with being dead, he resolves to live his life the best he can with the time he has remaining. [Written by MAL Rewrite]

Fear runs rampant throughout Tokyo with the revelation that demons in fact exist amongst us. Paranoia and the darker side of humanity boils onto the streets as people turn on one another, suspecting that anyone could in fact be a demon hiding in human clothing. Amidst the growing tensions, tragedy strikes Akira causing his mind to snap, retreating into his subconscious, allowing his Devilish alter-ego Amon to break free from Akira's cage of flesh and wreak havoc on both human and demons alike.

The world has become a slaughtering ground for the Crimson Denizens, mysterious beings from a parallel universe who thrive on the life energy of humans. These merciless murderers only leave behind scant remainders of souls called "Torches," which are mere residues that will eventually be destroyed, along with the very fact of the victims' existence from the minds of the living. In an ambitious endeavor to put an end to this invisible, hungry massacre, warriors called Flame Hazes relentlessly fight these monsters. One fateful day, Yuuji Sakai ceases to be a regular high schooler—he becomes trapped in a crevice of time and is suddenly attacked by a Denizen. Coming to his rescue just in the nick of time is a nameless hunter who seems no different from an ordinary young girl except for her blazing eyes and burning crimson hair. However, before Yuuji can learn anything more about his situation, he discovers that he has already been reduced to a Torch—merely a scrap of memory waiting to be extinguished. [Written by MAL Rewrite]

After a string of mysterious disappearances begin to plague a train, the Demon Slayer Corps' multiple attempts to remedy the problem prove fruitless. To prevent further casualties, the flame pillar, Kyoujurou Rengoku, takes it upon himself to eliminate the threat. Accompanying him are some of the Corps' most promising new blood: Tanjirou Kamado, Zenitsu Agatsuma, and Inosuke Hashibira, who all hope to witness the fiery feats of this model demon slayer firsthand. Unbeknownst to them, the demonic forces responsible for the disappearances have already put their sinister plan in motion. Under this demonic presence, the group must muster every ounce of their willpower and draw their swords to save all two hundred passengers onboard. Kimetsu no Yaiba Movie: Mugen Ressha-hen delves into the deepest corners of Tanjirou's mind, putting his resolve and commitment to duty to the test.