Nicolas has a happy existence, parents who love him, a great group of friends with whom he has great fun, and all he wants is that nothing changes. However, one day, he overhears a conversation that leads him to believe that his life might change forever, his mother is pregnant! He panics and envisions the worst.

In the peaceful world of Little Nicholas, there is Daddy, Mommy, the school, but above all, his band of friends. They are called The Invincibles, but above all they are inseparable. At least they think so. But when Dad gets a promotion and announces that the family is moving to the south of France, Nicolas' world falls apart. How can he imagine life without his best friends?

Somewhere between Montmartre and Saint-Germain-des-Prés, Jean-Jacques Sempé and René Goscinny lean over a large white sheet of paper and bring to life a mischievous and endearing boy, Little Nicolas. From schoolyard games and fights to summer camp pranks and camaraderie, Nicolas lives a merry and enriching childhood – and brings friendship and newfound life to his creators, too.

At school, Nicolas is falsely accused of misbehaving and is expelled. On school photo day, Nicolas will try to prove his innocence, with disastrous consequences.

It's the end of the school year. The long-awaited moment of the holidays is arrive. The little Nicolas, her parents and Grandma take the road towards the sea, and settle in for some time at the Hotel Beau-Rivage.