Kuina Ubuyashiki

Kuina is a young girl with fair, pale skin and a pair of large purple eyes. Her white hair is styled in a blunt bob, with bangs falling across her forehead, and she wears a long wisteria ornament on the left side of her head.

Her usual outfit is a purple kimono printed with a small flower pattern, layered over a white undergarment. The look is finished with a black sash, a pale accessory band beneath it, and a pink cord across the front.

Kuina is fiercely loyal to her brother Kiriya in his role as the new head of the household and commander of the Demon Slayer Corps. When the weight of leadership threatens to crush him, she does not shy away from forcing him back to his senses, even striking him so that he will not collapse under the strain of his duties during the climactic battle, as seen in chapter 181.

Born as one of the Ubuyashiki quintuplets, Kuina is among the youngest of the family. When her parents arrange to die in an explosion meant to trap Muzan, two of her elder sisters choose to remain with them, while Kuina and Kanata are sent to support Kiriya as he assumes the leadership title. They are moved to the hidden Butterfly Mansion under the protection of retired Hashira.

During the assault on the Infinity Castle, Kuina uses a talisman supplied by the demon Yushiro to help map the shifting fortress and relay information to the fighters. She demonstrates a remarkable memory for the structure even as it constantly rearranges itself. When Muzan's rampage leaves Kiriya in a panic, Kuina slaps him back to composure, an act she later regrets.

After Muzan finally falls to the sunrise, the surviving siblings gather the last two Hashira and formally disband the Corps. With the demonic threat ended, the curse on the Ubuyashiki bloodline lifts, and Kiriya lives into old age surrounded by family.