Kyojuro Rengoku/Relationships

Tanjiro Kamado
During their initial meeting at the Ubuyashiki Estate, Kyojuro develops a strong dislike for Tanjiro since he broke the Demon Slayer Corps rule of not protecting a Demon and such he rules in favor of killing Nezuko as well as in seeking punishment for Tanjiro. However, as the story progresses, he begins to take a liking towards Tanjiro after meeting him again on the Mugen train. The two boys develop a mutual respect for each other as fellow Demon Slayer Corps members, to the point where Kyojuro offers to make Tanjiro his Tsuguko. Tanjiro develops a strong admiration and affinity for Kyojuro, to the point where he calls him "Aniki" showing their brotherly bond. Tanjiro is greatly impressed by Kyojuro's swordsmanship and ability to smile on through the pain of fighting. Just before he dies, Kyojuro entrusts his will to Tanjiro, suggesting that he had grown very fond of the young Demon Slayer for the few hours they knew each other for.

Inosuke Hashibira
As with most new people he meets, Inosuke doesn't particularly like Kyojuro when he first meets him. However, when he sees Kyojuro protecting the people on the train and fighting Akaza, he grows to respect Kyojuro's strength and swordsmanship. After Kyojuro's death, Inosuke is the one to pick Tanjiro back up and remind him of the words Kyojuro had shared with them before he died and the fact that the Hashira believed in them.

Mitsuri Kanjiro
Kyojuro Rengoku was Mitsuri's mentor as she derived her own unique Breathing Style, The Love Breathing from his Flame Breathing. She has extreme gratitude for Kyojuro as well.

Akaza
Kyojuro hates Akaza because of their contrasting beliefs; the Upper Rank believes that weak humans just get in the way of others and that their existences are worthless where Kyojuro believes the weak and valuable and should be protected by the strong. Akaza takes a liking to Kyojuro because he can sense that his battle spirit is strong, and offers for him to become a Demon, but Kyojuro says that he would never sacrifice the beauty of humanity for immortality.

Senjuro Rengoku
Senjuro is Kyojuro's younger brother. Kyojuro cares deeply for him and fills in the role of his mentor for Flame Breathing. According to Senjuro himself, he failed to master the technique due to his lack of skills so he gave up. However, Kyojuro appears to still be proud of him.