Kayako Saeki (佐伯 伽椰子 Saeki Kayako?, née 川又 Kawamata) is a fictional character appearing in the Ju-on and The Grudge horror franchises. In all of the films, except for the third installment of The Grudge series, she is played by actress Takako Fuji. In The Grudge 3, Kayako is played by Aiko Horiuchi, Fuji having turned down the role. The only other time Fuji has not appeared as Kayako is in the web series Tales From The Grudge, where Kayako is portrayed by Anna Moon.
She was created by director Takashi Shimizu. She represents a popular antagonist in Japanese culture, the vengeful ghost (Onryō). She is typically characterized by long dark hair covering her pale face, unsettling wide eyes, twisted movements with crunching neckbones, and a haunting Death rattle. She first appeared in Shimizu's short movie Katasumi and spends the majority of the Ju-on series haunting a house in Nerima, Japan. She is one of the fulfillers of the Ju-on curse, which states that when someone dies in a state of intense rage, those feelings remain at the death site and kill whoever it touches.
She has proven to be a very popular character in horror cinema, having appeared in many films and other media in various different franchises.