Ju-on (Japanese: 呪怨 Juon, literally 'curse-grudge'), translated as The Grudge, is a series of Japanese horror films created by Takashi Shimizu (清水 崇 Shimizu Takashi). The plot centres around a curse born of someone dying in the grip of powerful anger, which follows anyone coming into contact with it. The film series is a well-known example of 'J-Horror' (Jホラー J Horaa), i.e. Japanese horror films.
Shimizu directed and produced the first two films, Juon (呪怨) and Juon 2 (呪怨2), in 2000 as low-budget straight-to-video releases, with the second film partly a remix of the original and partly a continuation of the story. These are sometimes also known as Juon: The Curse and Juon: The Curse 2. Shimizu eventually helmed a bigger-budget production partly as a further instalments and partly as a remake, Ju-on: The Grudge (2003). This spawned a sequel, Ju-on: The Grudge 2 (呪怨2) that year. One character, Kayako (伽椰子), appears in the Japanese films and the first two American remakes (see below), played each time by the actress and contortionist Takako Fuji (藤 貴子 Fuji Takako). In 2009, two indirect sequels were released: The Grudge: Old Lady in White (呪怨 白い老女 Juon Shiroi Roujo, 'white old woman'), written and directed by Ryuta Miyake (三宅 隆太 Miyake Ryuta); and The Grudge: Girl in Black (呪怨 黒い少女 Juon Kuroi Shoujo, 'black maiden'), written and directed by Mari Asato (安里麻里 Asato Mari).
Ju-on: The Grudge (2003), Shimizu's first cinematic work, spawned an American remake starring Sarah Michelle Gellar, The Grudge (2004). Some of the original Japanese cast reprised their roles as their characters as featured in the original films, while others were replaced by American actors portraying foreigners living in Tokyo. A 2006 sequel to this film partly remade material from the first Japanese Ju-on, but otherwise stood as a separate story, The Grudge 2 (2006), starring Matthew Knight. Unusually, since remakes often involve a change of production crew and storyline, Shimizu directed these films as well and kept most of the plots of the originals, particularly for the first film.
A second sequel, The Grudge 3 (2009), was executive-produced by Shimizu and helmed by British-born director Toby Wilkins. The film was shot entirely in Bulgaria with a local crew for budgetary reasons, with various locations standing in for Chicago and brief scenes in Tokyo. This was released direct to DVD and continues the story told in The Grudge 2; it included footage from the earlier Grudge films but the role of Kayako was played by Japanese actress Aiko Horiuchi. The film also starred Shawnee Smith and Johanna Braddy, with Matthew Knight reprising his role from The Grudge 2.