Laurent Chevalier is a nearly 15-year-old boy living in Dijon in 1954 who loves jazz, always receives the highest grades in his class and who opposes the First Indochina War. He has an unloving father Charles, who is a gynecologist, an affectionate Italian mother, Clara, and two older brothers, Thomas and Marc. Thomas and Marc are notorious pranksters, while Laurent engages in taboos such as shoplifting and masturbation. Laurent also witnesses Clara meeting with a lover, and upset with the adultery, runs to tell Charles. Charles, busy with his practice, angrily turns him away.