When Miguel (Suso Marín) dies in a solo scuba-diving accident, he refuses to go to heaven, blaming his guardian angel (Eduardo Tato) for doing a sucky job rather than his own impulsiveness. Wandering the Earth (well, Spain) in his scuba outfit (complete with flippers), he finds himself drawn to Patricia (Paola Verdú) the lonely wife of ambitious government worker Juan (Juan Dávila) who has been presumptuous enough to buy a family home without consulting her and often works late nights. Although Patricia is unable to see or hear Miguel awake, Miguel discovers that he can enter her dreams and proceeds to romance her in her sleep. As Patricia begins to retreat into her dreams, she misses work and her husband begins to get suspicious (even more so when she tells him that she believes Miguel is a ghost). Believing that Patricia might be having an affair (with a corporeal being), Juan hires a private detective; too cheap to hire a professional, he picks the part-time security guard "Vigilante" (Sepu Sepúlveda) who Patricia comes to believe is stalking her (and becomes the object of Miguel's supernatural pranks once he discovers he can interact with the physical world even if he can't be seen or heard).

STUCK TO YOUR PILLOW isn't an art film, it's a fluffy romantic comedy. Fortunately, it's sweet and funny without being too sickeningly cutesy (although it's a bit overlong at only one hundred minutes with the comic relief bits). Writer/director Mavi Navarro relies more on the performances and staging than visual effects; the camera cuts away before Miguel passes through anything or anything through him (similarly, the dream sequences are photographed in the same manner as the waking life scenes, so the transitions are effectively blurred with ringing cellphones so believably intruding on the dreams and denoting their status). The leads are attractive and go through the "romantic comedy" motions proficiently (although Miguel does become a bit of a manipulative jerk later in the film); the supporting actors shoulder the sight gags including donning Indian headdresses for a non-PC attempt at an exorcism. Subplots include Patricia's best friend Marta (Gemma Marin) stalking her ex-husband (Rafa Galán) and Vigilante's partner Socio (Rubén Torres) seemingly experiencing his own ghostly romance.