aurice (Michel Piccoli) is a composer, and a longtime member of the resistance. By chance, he shares a house with his teenager granddaughter. Claire, at 17, is eager to experience all sorts of things and the sooner the better, and rebels against anyone who wants to stop him. Between the swimming and the first encounters with the boys, she spends her life, hosted by his grandfather after being orphaned. But this interaction is difficult: both avoid themselves in their large house, escaping through the windows if necessary, living in mutual incomprehension. Yet, they have something in common: both are insurgents in their own way.

Overview from themoviedb.org