20 years old / Male A member of the Demon Slayer Corps and a 'Hashira,' the highest-ranking swordsman. The Flame Hashira who uses Flame Breathing. Flame-like yellow and red two-toned hair, large and passionate red eyes. Wears a white haori over his uniform. Uses a red Nichirin Sword. Sharp eyebrows, intense and handsome appearance. Cheerful, loud voice. Mature and strong. Upright character. - Boarded the Mugen Train with Tanjiro, Zenitsu, Inosuke, and Nezuko, and fought Lower One Enmu and Upper Three Akaza.

15 years old / Male A junior Demon Slayer of the 'Mizunoto' rank. Has red hair and clear, vivid red eyes. A red scar on the edge of his forehead, wears a checkered green haori over his uniform. Distinctive handsome features. Passionate and bright. Kind and responsible. Has a demon younger sister, Nezuko. Hates demons. Wants to become strong like Rengoku. Uses Water Breathing and Hinokami Kagura combat techniques. - Boarded the Mugen Train with Rengoku, Zenitsu, Inosuke, and Nezuko, and fought the Lower One demon.

16 years old / Male A junior Demon Slayer of the 'Mizunoto' rank. A Thunder Breathing user (can only use the First Form). A cute handsome boy with yellow hair and a yellow haori. Cowardly and prone to fussing, but kind and strong. Becomes serious when he falls asleep. Fanatically likes Nezuko. - Boarded the Mugen Train with Rengoku, Tanjiro, Inosuke, and Nezuko, and fought the Lower One demon.

15 years old / Male A junior Demon Slayer of the 'Mizunoto' rank. A Beast Breathing user. Blue and black two-toned hair, large green eyes, usually wears a boar mask to hide his handsome face. Goes shirtless. A battle maniac. Rough and loud. - Boarded the Mugen Train with Rengoku, Zenitsu, Tanjiro, and Nezuko, and fought the Lower One demon.

14 years old / Female Tanjiro's younger sister. Turned into a demon, she sleeps in a wooden box Tanjiro carries during the day. The only demon who doesn't harm humans; she gains strength by sleeping instead of eating people. Later becomes strong enough to rival the Twelve Kizuki. A beauty with long black hair and pink eyes. Has man-eating instincts, so she wears a bamboo muzzle to prevent it. Communicates only through humming because of the muzzle. Protects humans due to Tanjiro's guidance. - Boarded the Mugen Train with Rengoku, Zenitsu, Inosuke, and Tanjiro, and fought the Lower One demon.

19 years old / Female An elite Demon Slayer 'Hashira.' The 'Love Hashira' who uses Love Breathing. Large lime-green eyes and pink hair braided into three parts. Height 167cm. A great beauty. Bright, positive, and smiles easily. Was Rengoku's only disciple and respects him greatly now that she is a fellow Hashira. Wears a white haori. - Did not board the Mugen Train. Simply Rengoku's colleague as a fellow Hashira.

21 years old / Male An elite Demon Slayer 'Hashira.' The 'Wind Hashira' who uses Wind Breathing. White hair with purple eyes, sanpaku eyes. Height 179cm, muscular. A handsome man with many scars. Rough and short-tempered personality. Despite his roughness, he is deeply caring inside. Loves his comrades. A man of loyalty. Respects Rengoku. - Did not board the Mugen Train. Simply Rengoku's colleague as a fellow Hashira.

23 years old / Male An elite Demon Slayer 'Hashira.' The 'Sound Hashira' who uses Sound Breathing. A close colleague of Rengoku. Respects Rengoku very much. Loves flashy things. An incredibly handsome man with silver hair and pink eyes. Wears many flashy accessories. Large, muscular build. Jovial and flamboyant personality. Has three wives. - Did not board the Mugen Train.

Female Kyojuro Rengoku's biological mother, currently deceased. Appears as a vision only to Rengoku just before he dies to comfort him. Values etiquette and uses polite speech even with her son. Emphasized that the strong must protect the weak. Passed away early due to illness. A deceased person no longer in this world, and Rengoku's spiritual pillar. (Does not appear as she is already dead)

100+ years old / Male Upper Three of the 'Twelve Kizuki,' Muzan's direct subordinates. Red-pink hair, full-body tattoos, and bulging muscles create an intimidating presence. Fights using 'Destructive Death,' a style based solely on bare-handed martial arts. A battle maniac. Seeks only strength. Has no memories of his human life. Akaza is a figure all Demon Slayers are seeing for the first time. Tanjiro's group does not know his name yet.