The story is loosely based on a 17th century erotic Chinese story named The Carnal Prayer Mat and follows a young scholar named Yangsheng who gets married to the beautiful daughter of a local merchant. When their sex life proves unsatisfactory, Yangsheng leaves home and journeys to the Pavilion of Ultimate Bliss.

Eric (Alex Fong Lik-Sun) and Cheun (Sammy) are two medical students who opt to rent a flat in a secluded housing estate, the reason being to concentrate on their upcoming exams. Their best intentions go south damn quick; first of all, Cheun wastes time and acts extremely annoying, thereby ruining any chance at serious study time. Second, there may be vampires in the building. Eric becomes slightly enamored of Jade (Miki Lee), a pretty young thing who lives in the building with her older sisters (Zuki Lee and Cynthia Ho). But after a series of weird noises and the appearance of a man bleeding from the neck, Eric thinks something may be up. He enlists the help of TV occult expert Mister M (Yuen Wah), who all but confirms Eric’s suspicions: the sisters are vampires. Worse, they must suck the life out of one good man to cure their aversion to daylight, and have ear-marked Eric as the designated “good man”.