Sumihiko Kamado

Sumihiko is cheerful, easygoing, athletic, and habitually sleepy. Kanata Kamado repeatedly tries to wake him for school, yet Sumihiko still manages to oversleep and then wonders why nobody woke him.

He is reckless about his route to school but not deliberately rude. While sprinting through the neighborhood, he apologizes when his movements disturb people and generally maintains an upbeat attitude even as his increasingly spectacular shortcuts attract police attention.

Sumihiko is not especially interested in organized athletics despite his obvious physical talent. When encouraged to join a sports club, he objects that doing so would reduce the time available for sleeping.

Sumihiko possesses no established supernatural abilities or Breathing Style. Demons have disappeared from his everyday world, and there is no indication that he has received Demon Slayer training.

He is nevertheless exceptionally athletic. He jumps from his apartment window onto lower structures, swings from railings, runs across urban obstacles, vaults a police vehicle, and performs an acrobatic leap over his closing school gate.

These feats are presented as natural physical ability rather than evidence that he has inherited Sun Breathing or another supernatural combat technique.

Sumihiko appears in Chapter 205, which moves the story into modern Japan. After repeatedly ignoring Kanata's attempts to wake him, he realizes he is late for school and launches into an improvised parkour route across the neighborhood.

He encounters several descendants and reincarnations of people connected to the Demon Slayer era, turning his journey into a tour through the peaceful world created after the original conflict.

Sumihiko is the great-great-grandson of Tanjiro Kamado and Kanao Tsuyuri. The Kamado household still preserves Tanjiro's Nichirin sword, Yoriichi's hanafuda earrings, and a photograph of the people who survived the battle against Muzan.

Kanata Kamado is Sumihiko's older brother. Kanata repeatedly attempts to wake him for school and is considerably more responsible about their morning routine.

Tanjiro Kamado and Kanao Tsuyuri are Sumihiko's great-great-grandparents.

Toujurou Rengoku is Sumihiko's friend and schoolmate. The two meet while running late and vault the closing school gate together.

Touko Agatsuma and Yoshiteru Agatsuma belong to another branch of the extended family descended from people of the Demon Slayer era.