The film's foundation is the , a supernatural phenomenon born from "extreme sorrow or rage".

This report examines , the American remake of the Japanese horror classic Ju-On: The Grudge . Directed by Takashi Shimizu—who also helmed the original Japanese versions—the film is a seminal entry in the "J-horror" wave of the early 2000s. Core Premise and Mythology

: The primary figures are Kayako , known for her distinctive "death rattle" and crawling movements, and Toshio , the pale young boy who often appears with the cat. The Grudge 1 and 2 DVD Review - Spotlight Report

: Unlike traditional hauntings, this curse "gathers" where the victims died. It is inescapable and infectious; anyone who enters the cursed house becomes a target, and the curse can follow them elsewhere.

: The curse was created when Takeo Saeki murdered his wife, Kayako, their son, Toshio, and the family cat in a fit of jealous rage.