Charlotte Castang is a working-class 13-year-old girl, who lives in a drab, run-down neighbourhood, and is ready to become an adult. Her mother died giving birth to her, and she lives with her crass brother, and her father whose attention is elsewhere. Her only friend is Lulu, a sick 10-year-old she regards as a pest. Charlotte is antisocial, bored and dreams of a better life. Her life improves when she meets Clara Bauman, a pianist prodigy whom she admires. Charlotte wants to be friends with Clara, whom she sees as a potential route to prosperity, while the sophisticated Clara jokingly suggests that Charlotte should become her manager.