Utako, Takato's younger sister, was always delicate and confined indoors without any exposure to sunlight. Despite this, she remained upbeat and loving, leaving Takato content with their home situation. After returning home from a semester at boarding school, Takato observes a transformation not only in Utako but also in his two childhood companions who appear to be hiding something. Additionally, how does an aged and notorious local legend connect to all of this?