Mano Youko may seem like a typical 16-year-old high school girl, who is athletic, pretty, and boy crazy. She lives in a nice house with her mother Sayoko and her grandmother Madoka. But once you get past that, Youko is hardly normal. Many of the female members of the Mano family have been Mamono hunters, fighting evil spirits and demons throughout history. Youko learns that she was able to escape an earlier attack because her powers have been manifesting, and that now she is indeed the 108th generation Mamono hunter.