New student Anya, arriving in the middle of the year, disturbs the daily life of her fifth-grade class. After being hit in the head by a ball, she realizes that the playground is designed to favor boys, with girls relegated to the sides.

Sun, sea, homeschooling, Australia: That has been the life of ten-year-old Anya so far. But now, after years of traveling, her parents have decided to return to their native France, and Anya has to attend a public school for the first time in her life. But normal everyday school life quickly causes problems for the newcomer in the class. On the very first day, she gets a shot on the head with a soccer ball. When no one wants to apologize for this, a violent argument immediately ensues. So she messed it up with the soccer boys right from the start. Anya becomes an outsider, which doesn't even really bother her. But Zoé, Nils and Jade, who are neither among the girls who jump rope, nor among the soccer players, nor among the card players, take care of her. A new clique of friends is formed. But the pretty outsider would prefer to be friends with Nathan, the school director's son. But he gives her the cold shoulder because it wouldn't be cool to be interested in girls in front of his buddies. Meanwhile, the girls hatch a plan to win their place in the schoolyard. Under the eyes of the excessively overwhelmed teachers, a real fight ensues between the students and the class is soon strictly divided into genders. Now it's girls against boys. But how far can a dispute between children go?