As stories about ("The Slit-Mouthed Woman") spread through a Japanese town, an earthquake causes a corpse matching the entity's description to break out of a closet in an abandoned house. As this occurs, Noboru Matsuzaki, an elementary school teacher, hears a voice ask, "Am I pretty?" At a playground, a boy who had gone looking for with his friends is grabbed by the entity. The boy's disappearance prompts the school where Noboru works to send students home in groups, escorted by staff members. Mika Sasaki is reluctant to go home, admitting to a teacher, Kyōko, that her mother hits her. Kyōko has a troubled relationship with her own daughter, who lives with her ex-husband, and becomes agitated when Mika says she hates her mother, causing Mika to run away. Mika encounters , whose appearance was again
foreshadowed by Noboru hearing her voice. As leaves with Mika, Mika knocks her mask off, revealing the woman's disfigured face. At school, Noboru shows Kyōko a thirty-year-old photograph of a woman who looks like . Noboru hears the voice again and traces it to a house, and he and Kyōko save a boy from , whom Kyōko seemingly kills with a knife. 's body turns into that of a housewife, revealing that the spirit can possess the bodies of other women, signified by them developing a cough. Noboru tells Kyōko that the woman in the photo is Taeko Matsuzaki, his deceased mother, a sickly and unhinged woman who would physically abuse him and his siblings. One day, Taeko "disappeared" after killing Noboru's siblings, and after that, rumors and sightings of began. has now possessed the mother of Mika's friend, Natsuki. Natsuki is taken to 's lair, where the spirit cuts her mouth and murders the boy she had abducted from the playground. Mika saves Natsuki but she is traumatized and injured. Kyōko looks through information on and finds a note stating that the ghost's hideout is a deserted house with a red roof, a description that matches Noboru's childhood home. Noboru remembers that his mother tried to have him
mercy kill her, telling him that if he did not, she would come back and haunt others. Instead, Noboru slit his mother's mouth and stabbed her, then dressed her body up in a coat and mask, and hid it in the closet. Kyōko and Noboru find Mika in the house's basement, and are attacked by . captures Noboru and Mika and brutalizes them. Kyōko stabs the spirit in the neck, killing and leaving behind the body of Natsuki's mother. Mika's mother becomes the new host. Noboru fends off the spirit but is fatally wounded. Before dying, he beheads her, convinced that doing so will finally vanquish her. The decapitation fails to stop , as the only way to defeat is to obliterate Taeko's corpse in the closet, and the spirit possesses Kyōko while she is visiting her daughter, though it could be within a dream like sequence. ==Cast==