Sergio Benvenuti is a shy seller of contracts for a Roman company of music, but because of his character he cannot find even a customer, so he asks for help from a fellow named Nadia.
Working in the shadows of music stars, a gifted guitarist returns to his hometown and decides to stage a disappearing act in order to propel him to fame.
When an aspiring barber becomes inadvertently involved in the theft of a valuable diamond, necessity forces him to masquerade as a 12 year-old child - with humorous consequences.