Monsieur Gentil runs a perfume factory. He is a shy man, bullied by Madame Marthe, the manager, and spurned by Cléo, the young travel agent he is in love with. He 'd rather be a tough guy than a wet blanket and his meeting with Durante, a gangster, will be decisive. Considering him a providential piggy bank, Durante, following the advice of his boss Spinosa, entrusts the" education" of Gentil to two experts, Perrugo and Bersone.

Monsieur Gentil possède une grande usine de parfums que dirige tambour battant Mademoiselle Marthe. Timide et bourré de complexes, Monsieur Gentil essaie de plaire à Cléo. Il rêve surtout de pouvoir égaler les célèbres bandits siciliens. Brusquement, ce rêve saugrenu devient réalité.