The young ladies love Michael Cera. And they giggled along adoringly at the SIFF press screening for Charlyne Yi’s half documentary hybrid. The L.A. comedienne, glimpsed briefly in Knocked Up, pursues a twofold strategy in this semi-twee, semi-charming summer sleeper (set for Aug. 7 release). First she road-trips around the country, interviewing real couples about how they met and what their love means to them. Second, back home with her comedy-club cohorts (including Seth Rogen), still being trailed by a film crew, she meets and falls for Michael Cera. Swoon! Ever since Arrested Development (and later Juno), who doesn’t love that gangly, overgrown middle schooler? He brings instant goodwill to the screen. But his lightly ironic, air-quoted sincerity is one reason Yi’s film trips on its premises. She and Cera have been dating in real life. Here, their shy courtship is being not so subtly staged by Paper Heart’s supposedly real documentary director (actually an actor). But all the road-trip interviewees appear to be real (and we’d feel mightily cheated if they weren’t). And then, third level of artifice, Yi illustrates their love stories with cute little handmade paper cutout sequences that, inescapably, feel like Michel Gondry’s work. As a whole, Yi’s movie doesn’t hang together. But I think it’ll do a brisk business when high-school and college girls are on their summer vacations.Paper Heart Uptown 7 p.m. Sat., May 23 and 4 p.m. Sun., May 23.