In the south of France, by Nice, Hippolyte Ronchon, an old greedy man, lives with his seventeen year old niece Marguerite and her eight year old brother André, nicknamed Dédé, both orphans. Dédé learns to dance the Charleston on his own. Their neighbor Olive Papavoine, son of Baptistin Papavoine, a wealthy dairy farmer, is a shy, unattractive man who fancies Marguerite. Marius Papavent, the mail man, is also smitten with her. Marguerite is not interested in either of them. Saint Privais, a notary, writes Marguerite to tell her that her grand-father Evariste Guillaume Poupart has died and has left her 200,000 francs. The money is entrusted to her tutor Hyppolyte who agrees to give Marguerite 200 francs after Dédé’s insistence. The rest he plans to give her when she turns 21. That night, Dédé dresses Marguerite in Hyppolite’s fancy clothes and sicks a mustache on her so they can sneak out to town and go to a bar to celebrate. The two innocent kids try to befriend two prostitutes and their pimps, and one of the women finds out that Marguerite is really a girl and spills their drinks on her clothes. Before they hastily return home, they have to pay a 138 bar check! When Hyppolite finds out about this, he yells that he will send Dédé to boarding school and lock up Marguerite in her room. The pair escapes that very evening with Mandoline, their pet canary in her cage. After a long day’s walk, they spend the night under the open sky. The next day, as Dédé is coming back from town to buy some food, Marguerite meets Bamboula, a young homeless black boy. Thinking that he may attack his sister, Dédé frightens the boy away by talking about the police. After reading an ad in the paper, they decide to apply for a job as dancers at a local theater. M. Morioni, the generous manager offers them a 1,000 franc monthly salary to be on the show. The next day “Dédé 1st” and “Maguy” start rehearsing their act with Pilate, the unit manager and Décrin, the director. Dédé dances with Mme Piersowska in a parody of Maurice Chevalier and Marguerite appears in the finale in a beautiful dress. Meanwhile, Hippolyte’s hopes of seeing the children come back after their money runs out are wearing thin. Although he still does not want to call the police, he decides to go look for them himself and stumbles into a poster with Dédé’s name on it. He buys orchestra seat tickets for the show only to witness the kids’ success. As he calls for them from his seat, the frightened children leave the stage and he runs after them. The family returns home in a taxi as Hippolyte promises not to be so frugal anymore. They move to a richer, bigger house.