The scene where Kayako appears in the reflection of Eason's TV screen after he switches it off may be a reference to an almost identical scene from Ring.
When Rachel finds Samaras body in the well, her hand grips Rachels wrist, and there is a sudden flashback. When Aubrey visits Kayakos mother, she grabs Aubreys wrist, and there is a sudden flashback to her earlier days as an exorcist