They meet by a fenced-off crevasse. The boy is Age, a mopey student from a rigid society that discourages even glancing skyward. The girl is Patema, an explorer from an underground realm. From Age's perspective, Patema is upside down. From Patema's perspective, Age and his entire world are upside down, and she's about to fall off the fence and plummet up into the sky. Age grabs hold, the two of them hang suspended in mid-air, and Patema Inverted has its hook.

Patema's world is a substratum of service tunnels, artificial light, scavenged food, and dingy machines. Friends and elders alike warn her to not to tread too far into the unknown. Like any proper heroine, she ignores them. As she suits up and returns to a particularly interesting service shaft, an accident sends her down the hole and up into another land.

Age's world is a bright place of verdant fields, conveyor sidewalks, molding dormitories, sparkling office fortresses, and total compliance. Murals depict clawed tendrils snatching sinners into the sky, and no classroom goes without lectures of the superiority of the ground-focused society. This has little effect on Age, who's haunted by his father's unfortunate experiments with flight.

Director Yasuhiro Yoshiura doesn't detail exactly how Patema's personal gravity works—any in-depth explanation probably wouldn't satisfy science. Like his Pale Cocoon and Time of Eve, Patema Inverted doesn't dwell on the gears and flanges of an idea. It cares most about just where that idea takes the heroes and what it means along the way. Patema needs Age to keep her from flying off into the heavens, and Age needs Patema to finally break him free of the humdrum fetters of a society that conflates morals and physics. And once they're united, the film refuses to look down.

Patema Inverted plays its gimmick well. Linked like gravitational dance partners, Patema and Age bound across a dusty pit of communication relays to escape a government patrol. A villain drags Patema to the edge of a window, and a mirrored vertigo takes hold as she stands on the edge of the sky. The movie whirls around Patema and Age as they drift through swirls of clouds frozen by warring forces of gravity. Patema, Age, and the rest of the cast may not be any more expressive than the denizens of high-budget television anime, but Yoshiura's sense of motion sweeps and climbs and clings to its soundtrack as well as any expensive blockbuster.

It's not all forceful grandeur, either. Yoshiura gets the absurdity of Patema and Age's pairing, and there's plenty of humor, whether it's puncturing the soundtrack in a dangerously sentimental scene or sending Age scuttling around the ceiling in a security-camera standoff. It all keeps the movie from descending into the haughtiness of a student film or the soppy extremes of Juan Diego Solanas' conceptually similar Upside Down.

Most importantly, the novel vision of Patema Inverted weaves an engaging film from simple materials. We've all seen many, many tales of mismatched young heroes joined by mystic forces and driven to save their disparate worlds. It was an old standard even back when Hayao Miyazaki canonized it in anime with his Future Boy Conan and Castle in the Sky. Patema and Age go through their escapade without great leaps in personal growth, and the film's pretty mild in its struggles. Yoshiura favors relatively non-violent heroes, so Patema and Age and their allies have to resort to the ill-advised but momentarily effective maneuver of tackling armed enemies.

Patema Inverted isn't really about much more than flying. It lends itself to all of the allegories that science fantasy welcomes, but the worlds it builds are a bit too familiar. Age's stifling society is a standard regime in its quasi-religious propaganda, its deadened citizens, and its ranks of red-eyed Gestapo-like soldiers apparently on loan from Mamoru Oshii's Kerberos Panzer Cops films. Patema Inverted is the first Yoshiura creation with a dedicated villain, and for this the director gives us yet another power-mad dictator with a penchant for sadistic experiments.

But Patema Inverted doesn't have to dive into fractured psyches. Yoshiura tells us just enough when its characters embrace upside-down as they leap from an aeronaut basket, when Age backs to the edge of a skyscraper, when Patema scrambles in a reverse-gravity struggle for a knife, or when the movie rotates its view and turns the night sky into a bottomless chasm. Patema needs rescuing and Age has simple motivations, but both of them grow into the likeable explorers of new territory. They're far more memorable than the leads of Green Legend Ran, Origin: Spirits of the Past, The Boy Who Saw the Wind, and other films that couldn't escape Miyazaki's shadow. Patema Inverted may not have the sci-fi introspection of Yoshiura's prior works, but it has his talent for striking imagery and enjoyable twists.

Like its heroes, Patema Inverted succeeds by refusing to slow down or dig in deep. Gravity defiance pumps new life into a routine tale, and Yoshiura's endearing style and kinetic pace keep it aloft where a weightier, pensive movie would come crashing to the earth in a tangle of heavy-handed messages and backstory. Patema Inverted doesn't need such excuses. When you're flying, it doesn't matter why.