Kusui Kunato is the older sister of Hyoma Kunato and the twin sister of Hayato Kunato in the story Malevolent Spirits: Mononogatari. She was a gentle and caring person who looked after Hyoma in the absence of their parents. Before the main timeline, she was killed by a tsukumogami, specifically a spirit known as Karagasa no Tsukemogami. Her death is a formative tragedy that fuels Hyoma's intense hatred of spirits and drives his personal mission. In the narrative, she appears through flashbacks and memories, serving as a poignant reminder of the loss that shaped the protagonist. Kusui Kunato does not demonstrate any combat or supernatural abilities; her defining traits are her kindness and her role as a protective figure in her brothers' early lives.