The title is hint enough that the 10-year-old whose freckled face fills the screen at the opening of this finely wrought French film belongs to a young girl; 20 minutes in and her true gender is established.
We could be forgiven for wondering, because in the interim, the youngster has introduced herself as Mikael to the kids in the neighbourhood where she has newly arrived. (It will be some time before we learn her name is actually Laure).
Her father (Demy) is preoccupied at work, her mother (Cattani) largely bed-ridden by a precarious pregnancy and when "Mikael" is not looking after her sister Jeanne (Levana), she's hanging out with the local lads. Slowly the fiction she has created is beginning to entrap her.
Writer-director Sciamma is not much concerned to explore the reasons for the dissembling. The fact that pre-puberty and puberty are riddled with ambivalence about identity, sexual and otherwise, is taken as read, and the film explores the difference between sexuality and gender with a delicacy that would never seek anything so banal as an explanation. It's a testament to its effectiveness that when Laure begins to dress like a girl, she still looks to us like a boy: that's who
she is (as opposed to what she is).
The film's major interest, then, lies in the gathering tension as we wait for the inevitable. The family scenes of unforced intimacy are sharply contrasted with the kids' scenes in the playground and forest - indeed the apartment's bolted peepholed door is both a metaphysical and physical boundary between Laure's and Mikael's worlds - but summer's coming to an end and Laure will be enrolled at school, and soon the game will be up.