Yosuke, a newly hired male nurse with black hair and grey eyes, arrives at a remote hospital isolated from society. He is haunted by disturbing visions of torture and rape during his journey, visions that intensify within the facility. These psychological phenomena stem from a calculated scheme designed to lure him into participating in a clandestine experiment aimed at dismantling his control over primal urges.

By day, Yosuke performs standard nursing duties alongside female staff, maintaining the hospital grounds and caring for elderly residents. After nightfall, bizarre music broadcasts trigger overwhelming sexual compulsions in him and the female staff, stripping away their autonomy. Despite these coercive conditions, Yosuke struggles against the artificially induced desires while simultaneously attempting to investigate the hospital’s mysteries, including the origin and purpose of the manipulative music.

The experiment is orchestrated by elderly male figures—Aida, Tomii, and Kiba—who exploit the staff for sound-related testing. Their manipulations directly contribute to Yosuke’s progressive loss of self-restraint, casting him as both victim and investigator within the facility’s oppressive environment. His exact age remains unspecified.