Childhood friends Ken, Motoki, and Rin - estranged for years but now reunited 10 years later - are joined by the last of their group, Yuki, who has been missing since her disappearance at the House of Horrors a decade earlier. Her sudden reappearance in Rin's living-room as a frail, distraught woman, has set in motion a string of terrifying events. The group brings Yuki home, where a menacing-looking toy rabbit triggers a panic attack in Yuki and she falls down a flight of stairs.
Joined by Miyu, Yuki's younger sister, the five quickly rush Yuki to a hospital, where something seems terribly wrong. No one is there to help them and not a patient is in sight. In the midst of the confusion, Yuki disappears. The night of terror that ensues, where Ken, Rin, Motoki and Miyu must navigate the labyrinth-like corridors of the hospital as well as their own minds, are to confront their past, unearth long-suppressed memories, and test the resilience of their sanity.