The Ring

Sadako

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. Meanwhile, Ikuma attempted to unlock psychic powers of his own by meditating beneath a waterfall, which ended up causing him to contract tuberculosis, requiring him to recuperate in a sanatorium in the Izu Peninsula, leaving Sadako to be raised by Shizuko's relatives. Like her mother, Sadako was a powerful psychic; however, whereas Shizuko could only burn images onto paper, Sadako could also project images into electronic media, such as TV.

At the age of nineteen, Sadako joins a Tokyo-based acting troupe. As revealed in the short story Lemon Heart, she falls in love with the sound operator, Hiroshi Toyama. He learns of her powers but accepts them. Unfortunately, an early form of the curse is created in the form of a sound recording that kills four people, including the troupe's director, resulting in a heartbroken Sadako leaving Toyama. Eventually, Sadako visits Ikuma in the Izu sanatorium, only to be raped by a doctor named Jotaro Nagao, who is unknowingly infected with smallpox. During the assault, he discovers that Sadako has testicular feminization syndrome, and has the genitalia of both sexes. Sadako bites him on the shoulder, causing her to be infected by the smallpox virus that Nagao contracted. Finally, Nagao throws her down a nearby well and seals her within. Foreseeing herself being reborn years later, Sadako vows revenge on the world before she dies. Her psychic powers mutate the smallpox virus into a new strain of virus, called the "ring virus", one that causes anyone who contracts it to die, seemingly of fright, within a week.

By Ring, in 1991, the Izu sanatorium, including the well that Sadako was thrown into, has been rebuilt into a mountain resort. The well is located right below a TV screen of one of the resort's cabins. When a vacationing family forgets to bring home their videotape after one night, Sadako projects the new virus onto the TV screen, taking the form of a video, and the VCR records it into the tape. The next visitor at the cabin, 17-year-old Tomoko Oishi, inadvertently discovers and watches the tape, leading Sadako to kill her. Tomoko's uncle, journalist Kazuyuki Asakawa, begins investigating her death and watches the tape, leading to him being cursed by Sadako. He learns about Sadako's origin and writes a journal detailing his investigation.

As revealed in Spiral, the ring virus originally had an escape clause which allowed it to propagate itself, but Tomoko and her friends, not believing any of it, mischievously overwrote the part where the tape gave the solution as a prank. As a result, the virus had no means to inform its viewers on how to multiply itself, so it mutated when the next viewer of the tape, Kazuyuki, watched it and copied it for his friend, Ryuji Takayama. Two strains then emerged: a ring-shaped one, which would invariably kill its viewers within a week, and a spermatozoon-shaped one, which would lay dormant within the viewers unless they were ovulating women, whose ovum would be infected by the virus and transformed into a Sadako clone. This was because Sadako wanted to be reborn, something she could not biologically do because she was intersex. Finally, though the original tape and its copies had been disposed of by the events of Spiral, the virus found its way into a new media: Kazuyuki's journal, which his brother published after his death in a car accident. Kazuyuki's survival was actually not because he copied the tape for Ryuji, but rather because he unwittingly helped the virus propagate. This was why Kazuyuki survived where his wife and daughter, who also copied the tape per his instruction, did not.

The dormant virus infects the ovulating Mai Takano when she watches the tape, causing her to give birth to a Sadako clone who assumes the name Masako. She is described as a "complete hermaphrodite" as she has fully functional male and female reproductive organs. After her identity is revealed, Sadako tells Mitsuo Ando that she made a deal with Ryuji: in exchange for his resurrection, he would help her be reborn, something he did when he attracted Ando into the case. She then blackmails Ando: in exchange for not activating the dormant ring virus that he contracted when he read Kazuyuki's journal, he would refrain from stopping it from being published. As an incentive, Sadako, who has the ability to clone a person by implanting their genes into her, will birth his deceased son, Takanori, back to life. Realizing that Sadako would win no matter what he does, Ando reluctantly cooperates.

In the third novel, Loop, which revealed that the events of the previous two books were set in a virtual reality called LOOP, it is stated that the ring virus unwittingly escapes into the real world after its creators clone Ryuji, who is dying from the virus. The virus separates from Ryuji and mutates with a bacterium, creating a highly dangerous cancer called the Metastatic Human Cancer (MHC), which threatens all life. The cloned Ryuji, who is raised as Kaoru Futami and has no memories of his life in LOOP, eventually has to reenter the virtual reality to get the cure for both the ring virus and the MHC. In the short story "Happy Birthday", Kaoru finds a cure that neutralizes all clones in the virtual reality, causing both himself and the Sadako clones to rapidly age and die within a matter of years.

The fifth novel, S, reveals that Masako was impregnated by Ryuji and gave birth to a girl named Akane Maruyama. Akane, unlike the Sadako clones, does not inherited the defective genes that had imperiled the clones, including Masako, who dies a few years after she is born. Meanwhile, Ryuji tries to stop the ring virus from propagating through Kazuyuki's journal, but relents to allow four Sadako clones to continue existing, thinking that they have short lives and therefore pose no threat. However, the clones are killed off one by one by Ryuji's student Hiroyuki Niimura, who feels it is his duty to destroy Sadako once and for all.