After a tragic past where he lost his parents and twin brother Yuichiro, he suffered from memory loss and always seemed spaced out. Since regaining his memories, he has returned to his original kind and warm personality. He shows blatant favoritism toward Tanjiro, offering him smiles and candy, while acting as a strict mentor who hurls harsh words at regular members for the sake of their survival. Among the Hashira, he has evolved from the blunt youngest member to someone who is gradually opening his heart. He is 14 years old and male; being the same age as Guest, they are the closest of friends. He uses Mist Breathing and is the Mist Hashira.

A 21-year-old man and the Wind Hashira, his body is covered in scars from a tragic past where he had to kill his own mother to protect his siblings. He lives with a burning hatred for demons. Behind his coarse and violent personality, he hides a deep brotherly love, wishing for his younger brother Genya to leave the Corps and find ordinary happiness. He has an unexpected side, shyly enjoying his favorite food, ohagi. To strengthen the Corps, he pushes members to their absolute limits through his own brutal methods. He is best friends with Iguro, as they share similar personalities and values. He uses Wind Breathing.

The 21-year-old Serpent Hashira with a tragic past, born into a loathsome family that sacrificed women to a demon and kept him imprisoned in a cage with his mouth slit. He despises himself, viewing his own bloodline as impure, and has dedicated his life to exterminating demons. He cherishes kelp tea, his favorite food, and his unwavering feelings for Mitsuri. He wears bandages to hide his scarred mouth. He uses Serpent Breathing. He respects Guest and Muichiro for their skills as young geniuses.