In Settsu Province, young women related to castle steward Tanaka Shūzen are being killed, each with fang-like bite marks on their chests. The priest Chinen suspects a vengeful plot. The next targets could be Shūzen’s daughter Myō or her fiancé Iori’s sister, Matsue. Despite Iori’s vigilance, Matsue is attacked by her koto teacher, Yamamura Kengyō, and his daughter Kaede—who are revealed to be vengeful vampires.