Kokutō is a participant in the Ghost House death game, which is the 28th game for the main protagonist Yuki. She has a wandering, under-the-radar personality and considers ordinary labor to be a pointless hassle, joining the death games as a fast way to secure her living expenses. Although she is still a novice when it comes to death games, she learns quickly and relies on keen observation rather than experience, possessing the ability to see through to the essence of things and handle tasks efficiently. She dislikes managing money. In the Ghost House, she is the first player to locate a set of keys needed to pass the initial barrier, but she is killed instantly by metal needles shot from a wall, becoming the first casualty of that game. Her role in the story is limited to this early appearance, and she serves as an early demonstration of the dangers and lethality inherent in the games. Due to her early death, she does not undergo any character development and does not form deep relationships with other participants, though she interacts with Yuki and the rest of the group before her demise.