Rachel Gladstein, a shy little nine year old girl, loved by her cynic father and stifled by a possessive Jewish mother, meets at the start of classes Valérie, a fearless and shameless girl of her age. Rachel, influenced by her new girl friend, engages in turn to profanity, indecent gestures and nonsense, and opens up to life. She sleeps with her satchel on her back on the eve of the new school year, and must consult with the psychologist Ms. Trebla who will enter her privacy. In parallel, a friendship develops between the parents of the two girls, particularly between Michael Gladstein and Catherine, the divorced mother of Valérie. The nascent jealousy of Rachel's mother in the face of this closeness will bring her to question her own couple, which suffers from routine and weariness.