The fearsome yōkai known as hari onago appears at night on the roads of the island of Shikoku. In the dark, they are indistinguishable from ordinary young women, unusual only for their loose, disheveled hair. Upon closer inspection, the tip of each hair is fitted with a needle-like, barbed hook. Hari onago wander the streets searching for victims usually young, single men walking alone. When a hari onago comes across a suitable man, she smiles coyly at him. If the smile is returned she will kill