A theater troupe is in the midst of rehearsing a stage adaptation of the classic Edo-period ghost story "Yotsuya Kaidan." The lead actress, Miyuki Goto, is deeply committed to her role as Oiwa, the wronged wife, while her lover, Kosuke Hasegawa, plays Iemon, the unfaithful husband. As rehearsals progress, the lines between the actors' real lives and their characters begin to blur. Tensions rise when Miyuki grows increasingly consumed by her character, and Kosuke's off-stage infidelities mirror those of his role. The intensity of their performances starts to take a toll on their mental states, particularly on Miyuki, who finds herself unraveling emotionally.

Amid the intricate set pieces and haunting imagery of the play, supernatural elements start seeping into reality. Eerie occurrences and unexplained phenomena plague the cast and crew. Miyuki's co-stars and even the director struggle with disturbing visions and a growing sense of dread. The boundary between fiction and reality continues to disintegrate, leading to a series of unsettling events that leave everyone questioning their sanity. Unable to distinguish between the play's narrative and their own lives, the cast is caught in a harrowing spiral that threatens to consume them entirely.