In 1995 Tokyo, after a report of a possible child abuse happening in the Yamaga household, authorities and the schoolteacher of the family’s eldest son, Toshio, search the household to find it in a state of disarray. They find Toshio dead with his hands and feet bound in the closet of the second floor bedroom, apparently due to heatstroke.
Nine years later, a group of high school students: Nanami, Yayoi, Aoi, and Rina, visit the former Yamaga house, now taken for sale by Aoi’s older sister. Nanami, who is afraid of ghosts, is shoved to enter due to rumors of the house being haunted. While the others find drawings depicting horrific deaths and burst into laughter at the sight of each of them, Nanami hears a hum at the second floor bedroom. Upon seeing black liquid oozing, she tries to escape but panics when Toshio appears and grabs her. However, her friends are unaware and merely laugh it off as they leave the house in boredom.
During a basketball class, Yayoi sees something moving at the backstage hall. She finds the piano playing by itself and is grabbed by Toshio. Hurriedly entering an empty infirmary, she goes to bed and finds one of the creepy drawings of before and gets dragged away by Toshio under her sheets and disappears. Nanami and Aoi, meanwhile, find Rina having gone insane since the house visit and talking about a boy in white terrorizing her. While preparing a hot tea, Rina grabs milk from the refrigerator and while pouring in onto a cup it’s reveal that the milk it’s the black liquid from before, the teapot begins to heat up and the lid bursts. Rina’s face is burned by hot water and she disappears when Toshio drags her into the refrigerator. Aoi confides to her sister about the house, but her sister does not want to talk about it, while her brother-in-law, Kyosuke, is concerned at the prospect of Aoi having visited the house. At the bathroom, Aoi is confronted by Toshio, who kills her by ripping off her lower jaw and leaving it at the shower for her sister to find. Nanami, meanwhile, is terrorized by her dead friends on a train and is transported to the Yamaga house, where she is repeatedly slammed to the walls by an unseen force before being dragged away. Right afterward, Aoi’s sister guides two potential buyers, a couple named Takeo and Kayako Saeki, inside the house. The couple happily agree to take the house.
Ten years later, an elementary schoolteacher, Yui Shono, is assigned to replace Mr. Konishi as homeroom teacher of Class 3-3. She is concerned when she finds that a student, Toshio Saeki, has been absent for a week and decides to visit the Saeki household. She meets Toshio’s mother, Kayako, who acts strangely, and finds the second floor closet sealed with duct tape. Yui is startled by Kayako’s behavior of continuously drawing spirals at her diary and hastily takes her leave. She is informed the next day that Mr. Konishi has died. Yui begins to act strangely, having hallucinations of Toshio in the classroom and drawing spirals on her students’ exam papers. She finds Kayako’s diary at the classroom and enters a trance. Her boyfriend, Naoto Miyakoshi, is concerned and reads the diary, which reveals that Kayako, who could not have a child with Takeo, became pregnant when a boy in white “touched” her in a dream. He meets with the widowed Kyosuke who inquires about the curse that claimed his wife and her sister’s lives, and finds out that Toshio Yamaga and Toshio Saeki look identical, almost as if they are one and the same. While inspecting the photos, Naoto is killed when Kayako snaps his neck.
Yui, having recovered, visits the Saeki household and opens the second floor closet, discovering a box containing tapes that show the Saeki family’s lives. A hidden tape inside an envelope reveals that Kayako did indeed get pregnant not by Takeo, but by the spirit of Toshio Yamaga entering her. Yui experiences flashbacks of Takeo murdering Kayako and Toshio after he found out he was not Toshio’s father. She heads to the attic and finds Kayako’s body, who wakes and crawls towards her. Yui is cornered by both Kayako and Toshio, but suddenly wakes up at her apartment. Thinking everything was a dream, she goes outside, only to find Naoto, his head still snapped, walking towards her.