, reimagined as Park Eun-suh () and Samara Morgan for their respective adaptations, is the main antagonist of Koji Suzuki's Ring novel series and the film franchise of the same name. Sadako's fictional history alternates between continuities, but all depict her as the vengeful ghost of a psychic who was murdered and thrown into a well. As a ghost, she uses , her most distinctive power and weapon, to create a cursed video tape. Whoever watches the tape will die exactly one week later unless the tape is copied and shown to another person, who must then repeat the same process. Sadako Yamamura has been played by a number of actresses in films, including Rie Inō in Ring and Ring 2, Hinako Saeki in Rasen, Yukie Nakama in Ring 0: Birthday, Ayane Miura in Ring: Kanzenban, Tae Kimura in Ring: The Final Chapter and Rasen, and Ai Hashimoto in Sadako 3D. Foreign adaptations renamed the character, with Bae Doona portraying Park Eun-suh in the South Korean film The Ring Virus, and Daveigh Chase portraying Samara Morgan in the American films The Ring; Bonnie Morgan would later take over the role in Rings. The character also appears in Kōji Shiraishi's 2016 crossover film Sadako vs. Kayako portrayed by Elly Nanami, alongside Ju-On and The Grudge antagonist Kayako Saeki, both serving as principle inspirations for the webtoon series Erma. Sadako was born in 1947 to Shizuko Yamamura and Dr. Heihachiro Ikuma in Oshima Island. The year before, Shizuko gained psychic powers after retrieving an ancient statuette of En no Ozuno from the ocean. Shizuko also gave birth to a baby boy but he died four months later due to an illness. Planning to move to Tokyo with Ikuma, she entrusted her mother to take care of baby Sadako. At Ikuma's encouragement, Shizuko displayed her psychic powers during a publicized demonstration. However, Shizuko bowed out of the demonstration due to migraines brought on by her powers. The press denounced Shizuko as a fraud because of this. Depressed, Shizuko eventually returned to Oshima Island and committed suicide by jumping into Mount Mihara.