Taking place thirty years before the events of Ringu, Ringu 0 provides the shocking background story of how the girl on the video became a deadly, vengeful spirit.
Ring 0: Birthday is a 2000 Japanese supernatural psychological thriller film directed by Norio Tsuruta, from a screenplay by Hiroshi Takahashi, based on the short story "Lemon Heart" from the Birthday anthology by Koji Suzuki. A prequel to Ring (1998), the story follows the life of the character of Sadako Yamamura just before she consigned to her fate seen in the later Ring series.