Fifteen-year-old Sophie yearns to break free from her dysfunctional family. After one argument too many, she seizes an opportunity and takes the spare keys to her affluent friend Jade's house. While enjoying the spacious home she thought was empty for summer, she bumped into her friend's older brother Stéphane. He, as fate would have it, was also planning on staying. Rather than insisting she leave, Stéphane lets her into the house and his life....