Ayaka Ichijo Fuka Koshiba, a graduate student and prodigy with an alleged IQ of 200, is introduced to the cursed videotape by Master Kenshin Hiroyuki Ikeuchi on a televised variety show. He warns that while the tape has previously killed victims in seven days, a new variant has emerged from a darknet market and can kill the viewer in 24 hours. Skeptical but curious, Ayaka agrees to bring the tape home to investigate it at Kenshin's request.
That night, Ayaka's sister Futaba Yuki Yagi watches the tape out of curiosity. The footage shows Sadako climbing from the well in the first person, revealing Futaba's current location inside the house once she climbs over the edge. After this, Futaba begins seeing Sadako following her at school, taking the form of people she knows. This pressure pushes Ayaka to research the tape further, drawing her back to Master Kenshin's office. There, she encounters Oji Maeda Kazuma Kawamura, who is visibly frightened and threatening to throw himself from a building rather than face the curse. Ayaka talks him away from the edge by explaining how painful the ordeal would be and that he likely wouldn't die from that height.
Inside Kenshin's office, Kenshin attempts an exorcism on the videotape. He claims success, but Ayaka remains doubtful and decides to keep investigating. She reaches out to Roido Kanden Mario Kuroba, a germaphobic hikikomori who has also been studying the curse online. The two theorize about how the curse operates, drawing connections to the smallpox virus and considering how the digital age might shorten the incubation and spread more quickly.
During a tense moment, Oji reaches the 24-hour deadline and seems to survive, prompting debates about immunity. Ayaka and Kanden propose an immunization theory: by having more people watch the tape, the curse would spread thinner and many would mount a non-fatal response. To test a wider protection, Ayaka tells her mother to watch the tape with Futaba, and the family watches together. The apparent success leads Ayaka to upload the video online and urge others to view it as a shield against the curse. Yet Kanden cautions that the mystery of who sold the tape remains unsolved. Eventually, Ayaka discovers the truth: Master Kenshin himself was the one who distributed the cursed tape to generate viewership for his show.
Ayaka confronts Kenshin, and the revelation makes it clear that his spread of the curse was a calculated tactic to fuel entertainment and ratings. As he explains, this comes from a disillusionment with his father's shrine work—his father indeed ran “exorcisms” for cash and came into possession of the tape through victims. In his own words, spreading the curse was "his own brand of entertainment." > his own brand of entertainment
Kenshin collapses and dies from the curse, immediately undermining Ayaka's immunization theory and leaving the origin of the tape unresolved in a more personal sense.
Desperate for answers, Ayaka returns to Kenshin's father's shrine. There, Roido Kanden waits in full gas mask and lab coat, having grown bored with remote investigations. Ayaka calls her mother and sister to the shrine as the three—along with Oji Maeda and Kanden—attempt to solve the curse once and for all by rewatching the tape in the minutes before their deadlines, hoping that repeat exposure will finally save them.
An unspecified amount of time later, all of them meet via video chat to rewatch the tape. As the clock winds down, Oji realizes he has forgotten to rewind the tape, and his phone dies just as his countdown reaches zero.
A post-credits sequence shows a now-gigantic Sadako emerging from the well into a movie theater, causing the audience to panic. The screen flickers with a single, chilling word: END.
