Sadako Yamamura (山村 貞子), also known as Park Eun-suh and Samara Morgan, is the main antagonist of Koji Suzuki’s Ring novel series and the film franchise of the same name. Her name combines the Japanese words for “chaste” (sada) and “child” (ko). 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 nensha, her most distinctive power and weapon, to create a cursed video tape that will kill whoever watches it exactly one week later unless the tape is copied and shown to another person, who then must 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 as the villainous protagonist, 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 and The Ring Two; Bonnie Morgan would later take over the role in Rings.
Sadako Yamamura appears in Kōji Shiraishi’s 2016 crossover film, Sadako vs. Kayako, with the Ju-on antagonist Kayako Saeki. She is portrayed by Elly Nanami.