An over-arching smugness blights this comic investigation into true love. It stars performance artist Charlyne Yi, who adopts a faux childlike inability to understand affairs of the heart when she traverses the US to question couples, precocious kids, marriage-industry eccentrics and even bikers about "happy ever after" romance. Had she stuck to that brief, this hybrid of documentary and make-believe might have been a diverting insight into an emotion that no one quite understands. But she and director Nicholas Jasenovec go all meta-movie and pretend that Yi falls for Juno star Michael Cera, chronicling their courtship with a self-conscious coyness. The precise nature of Yi and Cera's real relationship has been much debated (the press in the States dubbed them "America's Twee-hearts"), but it's an irrelevance beside the superciliousness of the mockumentary conceit and the mediocrity of the pair's acting.

Paper Heart follows Nick and Charlyne on a cross-country journey to document what exactly "love" is. Interviewing ministers, happily married couples, chemists, romance novelists, divorce lawyers, a group of children and more, the determined young girl attempts to find definition and perhaps even experience the mysterious emotion.