Kuina Ubuyashiki is one of the youngest daughters of Kagaya Ubuyashiki. She currently serves her older brother, the current head of the Ubuyashiki Household, Kiriya Ubuyashiki. Kuina has features similar to the rest of her family, light, pale skin with a set of large eyes. She wears a white blunt bob with fringe covering her eyes. Kuina is usually seen wearing a purple, flower-patterened kimono like her twin sister. She adorns her hair with a short flower headpiece with two beads hanging off it. Kuina displays her strong sense of loyalty and devotion to her brother as the new head of the Ubuyashiki Family and Commander of the Demon Slayer Corps, by being the one to forcefully remind him of his duties as their leader. She even resorts to physical force to remind him of this by slapping him, in order to ensure he did not break down under the stress of his responsibilities.