It's a sun-dappled summer. Laure (Zoe Heran), a 10-year-old girl with close-cropped hair, watchful eyes and enigmatic smile moves with her parents and younger sister to an apartment complex in a suburb outside Paris.

In a lovely opening scene, Laure, perched on her father's lap before the steering wheel, learns about directional signals. Soon, she will experiment with directional signals of another sort.

Like most children, Laure takes advantage of the move to a new place as a chance to reinvent herself. Unlike most, Laure strips off her tank top and introduces herself all around as Mikael, the new boy.

Tomboy, an explicit movie about one young girl's latency period, is an affectionate character sketch from French director Céline Sciamma. She matter-of-factly presents Laure as a 'tween trying on the other gender as her younger sister might try on Dad's shoes.

The result is both playful and poignant. Sciamma presents Laure not as a tragic figure having a gender-identity crisis, but as a youngster whose identity as well as her gender identity is unfixed, a work in process.

In the summer heat Laure finds it liberating not to be burdened by a shirt. It's exciting to test her strength and athletic skills against boys. It's thrilling to steal into the woods with Lisa (Jeanne Disson), a winsome brunette interested in Mikael, to taste a first kiss. For this spy in the house of gender, it's transgressive fun to escape her pink room and as Mikael to enjoy the prerogatives of boys.

But probably not so much fun for her new friends if they learn Mikael's secret. Laure's fear of being found out gives the movie a tension that simmers in the summer heat.

Beautifully photographed by Crystel Fournier, Sciamma's film has a floaty weightlessness (as opposed to the heavyosity of Boys Don't Cry) that neither judges nor pathologizes Laure.

The same cannot be said of Laure's mother, nine months pregnant and perplexed by the implications of her daughter's imposture. Why would her eldest, so motherly to her kid sister, pretend to be a boy? Why would Laure in the guise of Mikael permit Lisa to put lipstick and rouge on her to make the new boy look like a girl?

Open-minded and open-ended Tomboy is a portrait of pubescence on the brink of chrysalis.