She is a vengeful ghost, or onryō, known for her signature appearance: a white dress and long black hair covering her face. Her curse is famously spread through a cursed videotape that kills anyone who watches it exactly one week later unless the tape is copied and shown to another person.
Sadako was the daughter of a famous psychic, Shizuko Yamamura. Her immense psychic powers were difficult to control, leading to a public incident where she unintentionally killed a journalist who called her mother a fraud.
She was eventually lured to an old well, hit over the head, and pushed in, where she was left to die. In some versions, she remained alive at the bottom of the well for 30 years. Her immense rage and hatred manifested as a psychic imprint (nensha) on a nearby videotape, creating the curse
