Alfons Zitterbacke is ten years old and a very imaginative child. He dreams of a future as a cosmonaut or successful sportsman, but also has to cope with some everyday problems. Other children mock him because of his name, he is friends with Micki who supports him. Alfons also has some conflicts with his family: his father complains about his weak muscles. Alfons is supposed to become a "whole man" - this includes a fishing trip and a dive into the swimming pool...