Little Nicolas (Maxime Godard) is loved by his parents and has a lot of fun at school with a group of friends. They include: Alceste (Vincent Claude) who wants to be a high-ranking official, Geoffroy (Charles Vaillant) who will inherit his father's business in the future, Clotaire (Victor Carles) who dreams of becoming a cycling champion but is always punished in class, Eudes (Benjamin Averty) who wants to be a gangster when he grows up, Rufus (Germain Petit Damico) who hopes to become a policeman like his father, and Agnan (Damien Ferdel), who is the top student in the class and never gets punished, is the teacher's (Sandrine Kiberlain) favorite student, and is also a big cockroach that other students hate. One day, Nicolas's mother (Valérie Lemercier) suggested that his father (Kad Merad) invite his boss and his wife to dinner at home in order to win the boss's favor and raise his salary; but what Nicolas heard and observed made him think that his parents wanted to have a little brother and didn't want him anymore. Frustrated, Nicolas asked his friends for help, and everyone gave him a bunch of suggestions, including sending flowers, cleaning, and even finding criminals to adopt his brother. At the same time, the Minister of Education also came to visit the school, and the class was replaced by a strict substitute teacher... This film is based on the comic book series of the same name created by French writer René Goscinny and illustrated by cartoonist Jean-Jacques Sempé. After the film was released in France, it won the box office championship for two weeks in France and was nominated for the 2010 César Award for Best Adapted Screenplay.