Grampa Theo is an old puppeteer who used to travel around Italy with his son, Leon and granddaughter, Nana putting on puppet shows. He and his son had arguments regarding Leon's dream to become a doctor. Grampa Theo did not want Leon to become a doctor. He wanted his son to take over his puppet shows, but Leon, who is completely uninterested to become a puppeteer, refused to do so. One day, Nana, then an infant, got very sick. Little Nana luckily recovered from her sickness later. The argument between Grampa Theo and his son got worse because of what happened to Nana before. It reached to the point that Leon left his family.

Few years later, Grampa Theo and Nana, now an older little child, moved near the Rossi family's house in Milan after hearing a rumor that Leon is in the city mentioned. By the request of Angeletta, Romeo searched for Leon. In the end, Romeo, with the help of Professor Casella, found Leon, who is now a doctor of poor children in Milan. Grampa Theo and Little Nana were reunited with now Dr. Leon. The father and son reconciled with each other.