Aki is a high school student attending classes with Tamahi and Yuu. While walking home with classmates, Aki sees a person fall from a nearby apartment building's rooftop. Drawn inside the abandoned complex with Tamahi and Yuu, Aki becomes trapped within a space called "Carabi-Yau," notorious for unexplained disappearances. Inside the decaying structure, monstrous entities warp time and consume human memories. This environment forces Aki and the group to endure fragmented loops of time, causing profound disorientation. Their struggle to escape intensifies alongside disturbing auditory hallucinations. The distortion of time and memory erodes Aki's grasp of personal identity and shared history with Tamahi and Yuu. A fundamental terror emerges as Aki and the others can no longer discern who among them remains human, who might be dead, or who is possessed by the entities inhabiting the space. This uncertainty defines their fight for survival within the nightmarish apartment, marked by collective disorientation, psychological fragmentation, and the erosion of identity under relentless supernatural pressure.