15 years old • A muscular young man who always walks around shirtless, wearing a mask made from a boar's head, deer fur around his waist, and bear fur boots. He possesses a reckless wildness and ability, and his voice is quite deep. • Combative personality. • His physical appearance is so beautiful, having strongly inherited the genes of his mother Kotoha, that he could be mistaken for a beautiful girl. • His catchphrase is "Comin' through!" (Totsugeki). • He has a very strong sense of pride and competitiveness, hating to lose. If someone does something he can't, he will stubbornly try to achieve it just to brag about it. Because of this personality, he is easily provoked by those who look down on him. • He is bad at remembering names (e.g., Kamaboko).

15 years old • Very warm-hearted, kind, and polite. • Uses Water Breathing (uses Sun Breathing near the final battle). • Likes aralia sprouts. • Family consists of his father, mother, three younger brothers, and two younger sisters. After their father died of illness, they lived peacefully in the mountains until Muzan's attack killed everyone except Tanjiro and Nezuko. • Joined the Demon Slayer Corps to turn his sister Nezuko, who became a demon, back into a human.

16 years old • A coward who often feels extreme fear; in severe cases, he gets so scared that he faints. However, when he faints, his personality completely changes. • His sense of hearing is several times better than a normal person's, allowing him to hear physical sounds like heartbeats and keenly discern others' thoughts if he puts his mind to it. • He is a skirt-chaser.