Kiriya Ubuyashiki

Kiriya is polite, disciplined, intelligent, and remarkably composed for his age. His upbringing emphasizes responsibility toward the Demon Slayer Corps, and he performs formal duties without the childish hesitation that might ordinarily be expected.

That composure does not mean he lacks emotion. Kiriya cares deeply for his parents and siblings, and circumstances later force him to suppress overwhelming grief because thousands of Demon Slayers depend upon the decisions being made around him.

He also has enough self-awareness to recognize when panic compromises his judgment. His sisters help stabilize him during moments of crisis, allowing him to resume his responsibilities rather than pretending he is unaffected.

Kiriya has no known Breathing Style or supernatural combat ability. His strengths are intelligence, memory, leadership, strategic coordination, and the unusual foresight associated with the Ubuyashiki family.

He can process information transmitted by numerous Kasugai Crows and use maps to track combatants across complex battlefields. His sisters assist him with this work, turning the Ubuyashiki children into an operational command center for the Demon Slayer Corps.

The Ubuyashiki family's long experience fighting demons also gives Kiriya access to generations of records, strategic knowledge, and organizational infrastructure despite his young age.

Kiriya first appears at Final Selection alongside Kanata Ubuyashiki, explaining the examination and distributing ore to the successful candidates. His appearance initially makes it easy to mistake him for one of his sisters.

He later remains largely behind the scenes as Kagaya Ubuyashiki directs the Corps and Amane Ubuyashiki assists with family responsibilities.

After Kagaya, Amane, Hinaki, and Nichika sacrifice themselves in the trap against Muzan, Kiriya becomes the 98th leader of the Demon Slayer Corps. Together with Kanata and Kuina, he directs the Corps during the Infinity Castle and final battles, tracking the fighters and issuing instructions through Kasugai Crows.

Kagaya Ubuyashiki is Kiriya's father and predecessor as leader of the Demon Slayer Corps. Kiriya is raised to understand the responsibilities Kagaya carries and inherits leadership after his father's sacrifice.

Amane Ubuyashiki is Kiriya's mother and helps prepare him for the obligations of the Ubuyashiki family.

Hinaki Ubuyashiki, Nichika Ubuyashiki, Kanata Ubuyashiki, and Kuina Ubuyashiki are Kiriya's sisters. Kanata and Kuina remain beside him during the final campaign and help him coordinate the Demon Slayer Corps.

Tengen Uzui and Shinjuro Rengoku protect the surviving Ubuyashiki children while the active Demon Slayers fight inside the Infinity Castle.