“Palo Alto” is light and airy and filled with surprises. The first film by 27-year-old writer/director Gia Coppola is a fresh path down the well-trampled trail of high school movies. What happens to its cast of young characters is not novel — we’ve seen similar stories of aimlessness, flirtation and risk-taking before. Here, it’s rendered with a filmmaker’s cool, keenly observant eye.

Coppola is a naturalist intent on capturing the rhythms of everyday life. Her script, based on James Franco’s collection “Palo Alto Stories,” chops the warm, dreamy haze of a California school year into cubist slices. The story, following multiple, multigenerational characters through mundane and significant moments, is drama staged with prankish, youthful irreverence. Each vignette feels open-minded and teasingly incomplete.

What motivates pretty soccer player April (Emma Roberts) to pull toward the school football coach (Franco, full-on creepy-charming)? Why would artistic Teddy (Jack Kilmer, son of Val, who has a great cameo) drive drunk? Or ride along while his wild-card buddy Fred (Nat Wolff) half-heartedly bangs his car into a concrete wall? If Teddy is obnoxious to the cop who pulls him over for DUI, how can he be kind and sensitive while working off his community-service sentence at the local library? How can April’s promiscuous semi-friend Emily (Zoe Levin) believe that letting Fred have his way with her represents some kind of validation?

The film doesn’t pigeonhole any of its characters with one-dimensional explanations of their irresponsibility, though it does suggest that their environment is conducive to jaded spiritual decay. Coppola shoots her players’ comings and goings from a remove that suggests anthropological distance or the perspective of a bemused passerby. She often uses emotionally relevant music to make her points; South African rap duo Die Antwoord’s “Enter the Ninja” sets just the right tone of adolescent agitation at a house party.

We’re never lectured about how we should respond to these bored, co-dependent teens. Yet we understand their half-formed emotions. The characters seem less like dramatic constructs than half-remembered classmates from your own high school days. These slippery slices of life feel like the most honest, relevant film portrait of adolescence in ages.