Siblings Antonio, Peppino, and Lucia live in the country near Naples. Lucia's son Gianni goes to Naples to study medicine, but he meets a ballet dancer there. They fall in love and when she goes to Milan, he follows her. Informed of this and afraid that their nephew will give up his studies, Antonio and Peppino leave for Milan to persuade Gianni to abandon the "Malafemmina" (bad girl, "hussy", etc.) and return to Naples and his studies.