Sleep

• Sleep had its world premiere in the Critics' Week section of the 76th Cannes Film Festival on May 21, 2023. Director Bong Joon-ho — for whom Jason Yu had worked as an assistant director on 'Okja' — publicly called it "the smartest debut film I've seen in 10 years."
• Writer-director Jason Yu drafted the script while preparing to marry his own longtime partner; he's said he wanted the film to show a married couple overcoming a crisis together rather than being torn apart by one, giving the horror an unusually romantic undercurrent.
• Sleep was one of actor Lee Sun-kyun's final film roles before his death in December 2023, a few months after the film's South Korean release. It became the country's 10th highest-grossing domestic release of 2023.
• 'Sleep' is Jason Yu's feature writing-and-directing debut and an original screenplay, not adapted from a prior novel or short story.
• The production design team hand-built the wall of paper talismans that covers the apartment late in the film, deliberately styling it to look like something a panicked Soo-jin had slapped up herself in a rush, per Yu's own account of the shoot.

The demon represents the repressed resentments of marriage, with the physical restraints symbolizing the inescapable vows that trap Soo-jin even as her husband becomes a monster.

Hyun-su's susceptibility stems from a generational trauma passed down through his family line, suggesting the entity is an ancestral debt rather than a random haunting.

The final confrontation implies that true exorcism requires the total destruction of the self, arguing that the man Soo-jin loved died the moment the possession began.

Newlyweds Hyun-su and Soo-jin are expecting their first child when Hyun-su starts talking, scratching himself bloody, and raiding the fridge for raw meat in his sleep — muttering that "someone's inside." A doctor diagnoses a treatable sleep disorder and prescribes medication, but after their daughter is born, Soo-jin's dread outpaces the medical explanation. A shaman convinces her a vengeful spirit has taken hold of her husband, and Soo-jin's fight to protect her family escalates into increasingly extreme measures — papering the apartment in protective talismans, restraining her husband at night, and finally turning on the downstairs neighbor she believes is tied to the haunting. Writer-director Jason Yu never confirms whether Soo-jin is battling a genuine possession or her own unraveling mind — the ambiguity is the point. "Sleep" turns a marriage's most mundane fear, that you don't really know the person lying next to you at night, into a slow-motion domestic horror.