CORPSE PARTY

Kisaragi Academy student Naomi Nakashima awakens in the cursed Heavenly Host Elementary School, remembering that she and her classmates performed a friendship charm called "Sachiko Ever After" before being engulfed by an earthquake and separated. Reuniting with her friend, Seiko Shinohara, the two search for an exit together, but find that all the windows and doors in the building are sealed. While they are resting in an infirmary, Seiko notices she has lost her paper charm slip and leaves Naomi to look for it. Naomi is then attacked by a ghost and, narrowly escaping with her life, encounters a girl in a red dress. When Seiko returns, Naomi argues with her and the two go their separate ways. Wanting to apologize, Naomi finds Seiko hanged in a bathroom stall. 

The surviving Kisaragi students learn that Heavenly Host is the site of a murder incident where school teacher Yoshikazu Yanagihori allegedly cut out the tongues of four students. Ayumi Shinozaki and Yoshiki Kishinuma are attacked by the ghost of one of the victims, Ryou, but are rescued by the ghost of Naho Saenoki, a famed blogger who posted the Sachiko Ever After ritual online. They later find a bag of the children's severed tongues, which they use to appease Ryou's spirit. Meanwhile, two of the other victims, Yuki and Tokiko, kill Mayu Suzumoto by smashing her body against a wall, while her teacher Yui Shishido is struck in the head by the undead Yoshikazu. After the girl in red separates Yuka Mochida from her brother, Satoshi, Yuka is pursued by Sakutaro Morishige, who has snapped after discovering Mayu's remains. She is rescued by Yuuya Kizami, a student from Byakudan Senior High School, who proves to be insane himself when he stabs Sakutaro to death and declares Yuka to be his own little sister

Yuka runs away from Yuuya, who is knocked unconscious by Yoshikazu. Meanwhile, after restoring three of the four children's tongues, Ayumi and Yoshiki find themselves back at Kisaragi Academy. They are approached by Yuki, who shows Ayumi a vision that reveals the true murderer as Sachiko Shinozaki, the girl in red. Following an argument with Yoshiki, Ayumi returns to Heavenly Host to save the rest of their friends by herself. In Heavenly Host, Naho sends Satoshi to reunite with Naomi. Yuka is captured and tortured by a partially skinned Yuuya. Yoshiki arrives and kills Yuuya before he sacrifices himself to protect Yuka and Ayumi from Yoshikazu. Satoshi, Naomi, and Ayumi find the mortally wounded Yuka, who dies in her brother's arms. 

Ayumi tells Satoshi and Naomi that in order to return home, they must appease Sachiko and perform the Sachiko Ever After ritual again using their paper slips. Ayumi confronts and vanquishes Naho, realizing she purposefully lied about how to properly perform the ritual in her blog. Ayumi later briefly encounters Yui, who is decapitated by falling debris. Exploring the school basement, Naomi finds a video of herself hanging Seiko while possessed; she breaks down until Seiko's spirit relieves her. After the trio put Sachiko's spirit to rest, the school begins to collapse and the trio begin the ritual. Satoshi gives his slip to Naomi, who had lost hers, and intends to use Yuka's slip for himself, unaware that it is actually Yuuya's. Naomi and Ayumi both successfully return to Kisaragi Academy, but because Satoshi used a slip belonging to someone from a different school, only his detached arms come with them. A post-credits scene shows Naomi catatonic in her room, her mother disbelieving the existence of her dead classmates.