Sadako, originally known as 'Ring', is a renowned Japanese horror franchise that started with the novel by Koji Suzuki. It centers around a cursed videotape that leads to the viewer's death within seven days, unleashing the vengeful spirit of Sadako Yamamura. The franchise includes multiple adaptations, including films, mangas, and animes, each exploring different facets of the chilling narrative. The original story's groundbreaking blend of traditional ghost folklore and modern technology captivated audiences worldwide.