As a member of Amami Tribe, she has blue hair and gills on neck.
After her mother's death, she does not want to see any one else get hurt or killed. She is kind and will help anyone within her reach.
She deeply respects Kitarō and has developed a feeling for him.
Miu received the Jigoku Key from her mother as she passed away. After Kitarō was on the verge of death after exhausting his spirit energy from overusing his Finger Guns, Miu passed on the Jigoku Key to him.
She appears in episode #32 of the fifth anime adaptation, Landing! The Threat of Western Yōkai.
As a member of Amami Tribe, she is a powerful yokai. Her featured abilities are healing, swimming, underwater respiration, telepathy, and combat capability; she instantly heals Kitaro's wounds and repairs chanchanko, easily witstand Kitaro's internal electricity even with his chanchanko enhancing his spiritual powers, and delivers powerful blows in close combat.
- Etymology of both Miu and Kai are likely from "Ocean" in Japanese as the kanji 海 can be read as "Umi" or "Kai".
- Although Miu is an anime-original character, she has notable similarities in backgrounds to Mary, Kitaro's wife from After GeGeGe no Kitarō; both Miu and Mary loves Kitaro, they are heirs of tribal leaders of tropical islands, their islands are connected to the other world, Kitaro nearly died or actually died and resurrected in the events, and Amami Tribe is close to humans.