Kyōjurō Rengoku

"Set your heart ablaze!"- Kyōjurō Rengoku, Demon Slayer Kimetsu no Yaiba: Mugen Train

Kyojuro Rengoku was a major supporting character of Demon Slayer: Kimetsu no Yaiba and a major character in the Mugen Train Arc. He was a Demon Slayer of the Demon Slayer Corps and the former Flame Hashira. Kyojuro was a young adult of tall stature and athletic build. He is known have an air of great optimism about him, having an enthusiastic smile plastered on his face nearly all the time. He had long bright yellow hair with red streaks akin to flames along with two shoulder-length bangs and two chin-length bangs on the side of his head, black forked eyebrows, and golden eyes that fade to red with white pupils.

Kyojuro wore a paler brown version of the regular Demon Slayer uniform, which consisted of a brown gakuran jacket, a white belt around his waist and hakama pants. Over this, he wore a haori with a white-yellow gradient pattern and red flame-like ridges at the end that his father Shinjuro once worn and more than likely his father worn when they were the Flame Hashira respectively. Finally, he wore red kyahan with yellow flames erupting from the bottom-up, with pale brown tabi socks and a pair of white zōri with red straps.

When he first joined the Demon Slayer Corps, he only wore the regular Demon Slayer uniform but as he rose up the ranks, Kyojuro started wearing a completely white haori before donning on his signature flame-patterned one.Kyojuro was greatly enthusiastic in regard to his duties as a Hashira, and often came across as cheerfully eccentric. He was amiable, pure of heart and boasted extraordinary technique and swordsmanship stemming from strict practice and discipline. He was an honorable warrior who adhered to his code of morals and principles that was instilled into him by his mother at a young age—the most significant being his belief that those who were born strong have a duty to protect the weak.

Kyojuro also loved his family immensely, displaying great respect and worry towards his father, Shinjuro Rengoku, despite him growing slowly more aggressive and apathetic towards Kyojuro. He is incredibly encouraging and optimistic towards his little brother, Senjuro Rengoku, believing in him and wishing him the best no matter what. This is further accentuated during his death where his final words for his father and his little brother were "take care of your body" and "follow your dreams no matter what". Kyojuro also believes that if someone lacks immense skill, their hard work towards their dreams and desire to help people doesn't count for nothing.

Beneath his enthusiastic demeanor, Kyojuro is very logical and tactically intelligent, acting quickly and precisely in battle, especially when the lives of others are on the line. Kyojuro also is great in seeing talent in others, even in Nezuko, a Demon which he wanted to kill beforehand after seeing her risk her lives to fight Demons. Though he is extremely optimistic, Kyojuro does sometimes have a sense of foreboding that those he believes in might die, especially his friends which he care deeply for. Lastly, he, like most Demon Slayers, absolutely detest Demons, usually because of their heinous deeds or because of their clashing morale values. Overall Abilities: As a former Hashira of the Demon Slayer Corps, Kyojuro was a very powerful swordsman. Even demons as strong as Akaza, Upper Rank Three and the fourth-strongest of the known demons, acknowledged Kyojuro's strength. He even went as far as to offer to turn Kyojuro into a Demon so he could surpass his human limits and become stronger, something he only offered to swordsmen whose abilities he believed were refined to their utmost. Akaza also complimented his battle spirit and stated that it is getting close to the "Realm of the Highest," which implied that he was incredibly close to obtaining the Transparent World and the Selfless State. His father, Shinjuro Rengoku, stated that, after his son abandoned what he taught him, Kyojuro trained himself to become a Hashira after reading through an instruction book of the Flame Breathing style, a book which only had 3 volumes.

Extrasensory Perception: Kyojuro had incredibly honed senses, such as when he was able to sense and perceive Akaza's immense presence and demon aura which he uses to discern that he was an Upper Rank. Kyojuro was also capable of sensing demonic presences faster and more accurately than Tanjiro Kamado, who harbors an acute sense of smell, when he detected two demons right after another on a train before anyone else noticed. This ability also allowed him to precisely gauge the regenerative abilities and weaknesses of most demons, like Enmu. Kyojuro was also able to perceive Tanjiro's injuries and torn blood vessel accurately, which allowed him to teach him how to plug up that wound and prevent him from dying of blood loss. Furthermore, he was able to detect malice in Enmu's spells and prevented himself from getting incapacitated through detecting the malice of his spell.