Kyojuro Rengoku was a major supporting character of Demon Slayer: Kimetsu no Yaiba and the deuteragonist of the Mugen Train Arc. He was a Demon Slayer of the Demon Slayer Corps and the late Flame Hashira. Kyojuro was a young adult of tall stature and muscular-athletic build. 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. He was known to be charismatic and had an air of great optimism, having an enthusiastic smile plastered on his face nearly all the time.