Meet cutie Adriana Ugarte in hot but tender Castilos de Carton.

Paper Castles" feels as flimsy as its title. Sexually frank but chilly pic about hormonal awakenings among art-school students manages to be both weightless and airless, and the best efforts of its three young leads are not enough to save it from an uncharacteristically overwrought script by Enrique Urbizu that does little more than fashion their doubts and sufferings into a kind of retro stylishness. Offshore pre-sales for this end-October local release have been brisk.

Setting is '80s Madrid but, unlike in Almudena Grandes' source novel, the characters rarely seem to rep the uncertainties of a generation tied to changing history. As helmed by Salvador Garcia Ruiz, film remains tightly focused on the central love triangle.

Maria Jose (Adriana Ugarte), gentle, insecure Marcos (Nilo Mur) and slightly more outgoing Jaime (Biel Duran) are art students who fall, virtually without explanation, into a menage a trois. The first sex scene, played in real time, has Maria Jose and Marcos later joined by Jaime, and is compellingly played; later ones can't match it.

Maria Jose's inability to reach orgasm turns into a competition between the boys; Marcos also has sexual problems. Issues of art and truth are discussed at great length but with little insight. Eventually, Maria Jose's mother (Pepa Pedroche) asks when she's going to bring her boyfriend home -- a tough decision that ripples through the remaining reels as the end of college looms.

Chemistry between the three leads is the pic's strongest suit, as the trio move credibly -- and sometimes powerfully -- from suspicion to interdependency and back to suspicion. The vivacious Ugarte does good work in the taxing role of a young woman timidly negotiating her own sexuality, while Duran and his seaching gaze bring some spark to the otherwise dramatically muted proceedings. Weakest of the three is Mur.

The interiors of Jaime's apartment, where much of the action takes place, are appropriately painterly, textured and beautifully framed and lit. But it's a relief when the film moves outside into nighttime '80s Madrid, with its fun-filled bars.