To arrange the inheritance because of the loss of her mother, high school student Kei Hat? heads for her father's house in Hemizuka. In the train on the way there, Kei has a mysterious dream of a huge tree and a woman who seems to be lost in sadness. In Hemizuka, Kei learns the secret concealed in her own blood through various meeting with an Oni Slayer, a friend of her late mother, a young girl accompanied by a white fox, and even the mysterious girl from her dreams. (wiki)