A high school girl named Mizuho arrives at the emergency room late at night, but ignores the nurse's instructions and sneaks out of her room. Drawn by strange sounds, she finds herself surrounded by hospitalized patients who lead her to the Black Misa Ward. There, she encounters shocking scenes of naked patients wandering freely, others locked in cages, and explicit acts such as forced blowjobs, sister lesbian encounters, bareback penetration, and rimjobs. In this ward, a bizarre ritual takes place—offering bodies granted by God to the Devil—as Satan worshippers indulge in lewd acts. Amidst it all, Mizuho finds herself gradually losing control of her own body.