Kyojuro Rengoku

Like other demon hunters, Rengoku uses one of the five main senses. In a man, it is vision, which was demonstrated many times in the Infinite Train arc. First, when the conductor punched the tickets, Tanjiro smelled the smell, and Rengoku opened his eyes. Then, when he gave advice to the young Kamado on how to restore the damaged vessel. Kyojuro said that's it, when Tanjiro found the damage and restored it. It feels like the pillar has x-ray vision. The anime perfectly demonstrated the fight between Rengoku and Akaza, where the former used vision. Kyojuro was able to stop the demon when he was about to finish off Tanjiro. In the fight, the pillar quickly figured out how the enemy attacks and could follow his actions. Rengoku's eyes are wide open, thanks to which the man can notice any change. For example, Akaza's blows to the air. Also, Kyojuro's eyes are always directed in the direction where the demon or opponent is standing. Even the rapid movement of the enemy remains noticed by Rengoku. His eyes instantly switch to the target, which already amazes and bewilders both allies and demons.

Flame Breathing (炎ほのおの呼こ吸きゅう, Honō no kokyū?) is one of the basic breathing techniques. This breathing has been inherited in the Rengoku family since ancient times and was passed down to Kyojuro from his father. The fighting style of Flame Breathing users is based on delivering the strongest possible single strikes, as well as their combinations.

Kyojuro possessed such incredible speed and reflexes that even a highly trained and gifted Demon Slayer like Tanjiro could not follow him with his eyes. Kyojuro could even cause the ground to shake and nearly derail a train by moving faster than the eye could see. His reflexes were so fast that he managed to cut off Akaza's arm just before the Upper Moon was about to kill Tanjiro. Kyojuro was also able to keep up with Akaza's high-speed techniques, which the Pillar noted were faster than the blink of an eye, sometimes even managing to outpace him. Inosuke Hashibira himself noted that Kyojuro was on a completely different level due to his powerful attacks and speed. Kyojuro's phenomenal movement speed and reflexes even surprised and impressed Akaza, who openly expressed his surprise.

As a Pillar who had spent years perfecting his physical strength, Kyojuro possessed amazing strength, being able to swing his katana at speeds faster than the human eye can see, and terrifying precision during combat. Kyojuro also possessed a grip strength that was capable of holding Akaza, one of the strongest characters in the series, Upper Moon 3, despite his solar plexus having been pierced previously, to the point of absurdity that Akaza expressed his disbelief and shock at the strength, which he described as "incredible".

Kyojuro is a young, tall guy with a strong build. The most striking feature of his appearance is his bright yellow hair with long strands turning red in places. He is also distinguished by thick forked eyebrows and wide-open eyes.

Kyoujuro wears a lighter, brown version of the Demon Slayer's normal form. Over his uniform, he wears a cloak with a flame-like pattern and ridges at the hem, which was once worn by his father, Shinjuro, and most likely his ancestors. On his feet, Kyoujuro wears red tabi socks with yellow flames erupting from the bottom up, with a pair of white dzouri with red straps.

Kyojuro is a kind and honest man. He is quite eccentric, and tends to let his emotions run wild. However, Kyojuro has an unwavering optimism and tremendous fortitude, instilled in him by his mother at a young age, which helps him not only find strength in himself in difficult situations, but also support those around him.

Kyojuro is very enthusiastic about his duties as a Pillar and Demon Slayer. His worldview is based on the idea that the strong must protect the weak, instilled in him by his mother as a child. From his father, he inherited the discipline and steadfastness that he had acquired through training.

During their first meeting at the Ubuyashiki Estate, Kyojuro held a dislike for Tanjiro as he broke the Demon Slayer Corps' rule to protect his demon sister, and thus he insisted on killing Nezuko Kamado as well as seeking punishment for Tanjiro. However, as the story progresses, he begins to warm up to Tanjiro after meeting him again on the Infinite Train. The two hunters develop a mutual respect for each other as comrades in the Demon Slayer Corps, to the point where Kyojuro offers to make Tanjiro his Tsuguko. Tanjiro develops a strong admiration and closeness for Kyojuro, to the point where he calls him "Aniki" (big brother), showing their brotherly bond. Tanjiro is greatly impressed by Kyojuro's swordsmanship and his ability to smile despite adversity. Shortly before his death, Kyojuro entrusts his will to Tanjiro. Soon after, Kyojuro's tsuba is passed on to Tanjiro by his younger brother Senjuro.

Kyojuro's mother, who passed away from an illness when he was young. As shown in his memories of her, she was very strict towards him, yet loving and gentle towards him at the same time. She had a great influence on his overall philosophy, as she explained to him that he was born strong to protect the weak and to never use such a gift for selfish purposes. She loved Kyojuro deeply, as she tearfully expressed her gratitude for being blessed to have given birth to him as a child, a man born to be strong, kind, and gentle at the same time. Kyojuro cared deeply for her and loved her in return, as her words towards him gave him the final push to hold back Akazu in a final attempt to kill him despite his grievous wounds. In his final moments, Kyojuro saw his mother's spirit, who expressed that he had accomplished all the tasks she had set for him, and she was very proud of him, allowing him to die with a smile on his face.

The former Flame Pillar and Kyojuro's father. When Kyojuro was young, he and his brother trained under their father, who he described as a passionate man. After the death of his wife and his departure from the Demon Slayer Corps, their relationship became distant. Even after Kyojuro succeeded him as the Flame Pillar, Shinjuro paid no attention to it. After Kyojuro's death, Shinjuro insulted his son in a drunken stupor and seemed unconcerned about his passing. Kyojuro, on the other hand, never stopped caring for his father even after he became distant, and his final message was for him to take care of himself and his body. Upon hearing this, Shinjuro regretted his harsh words and mourned his deceased son. During the final battle against Muzan, Shinjuro joined the Demon Slayers alongside Tengen Uzui as the last line of defense protecting Kiriya Ubuyashiki, vowing not to bring shame to the Rengoku family or Kyojuro's memory.

Senjuro is Kyojuro's younger brother. Kyojuro loved and cared for him very much and mentored his younger brother in the Breath of Flame. According to Senjuro himself, he failed to master the Breath due to his lack of skill, so he gave up. However, Kyojuro was still proud of him. He was deeply saddened and depressed after learning of his brother's death.

Kyojuro Rengoku was born into the family of the Flame Pillar Shinjuro Rengoku.

As children, Kyojuro and his younger brother Senjuro were trained by their father in the art of swordsmanship so that they could follow in his footsteps and become demon hunters. At an unknown time when Kyojuro was still young, his mother Ruka gave him final instructions to protect the weak whenever possible and not to use his power for selfish purposes. After Ruka's death, Kyojuro's father began drinking and soon resigned as the Flame Pillar and stopped training his sons.

Despite this, Kyojuro, using the records of breathing techniques, mastered the flame breathing on his own and became a skilled swordsman. After this, he achieved the rank of Flame Pillar, like his father and their ancestors.

The Pillars are the nine most powerful swordsmen among the Demon Slayers, supported by the Demon Slayers. Each Pillar has a unique breathing style, which they perfect and develop through extreme training. Behind this group is the leader of the Demon Slayers, Kagaya Ubuyashiki himself.

The Pillars are constantly looking for a Tsuguko (successor) to take their place after their death or retirement. Each Pillar is assigned to a specific region that they are charged with protecting.

They must also gather information about demons and improve their sword skills. To become a Tsuguko, you must either apply and the Pillars will approve you, or they will find you and take you for training. Also, the same breathing styles as the Pillar can help in choosing a successor, but they can still take a person with a different style.

The Hashira (柱はしら, Hashira?), also known as Hashira, are the strongest and highest-ranking swordsmen in the Demon Slayer Organization, serving as their elite warriors. As such, they are the highest-ranking swordsmen in the organization, each playing a key role in their battle against the progenitor of demons, Muzan Kibutsuji.