Mio, my Mio
 Mio, My Son starts by introducing Bo Vilhelm Olsson ("Bosse"), a young boy who has been adopted by an elderly couple who dislike boys. They harass him, and tell him to stay out of their way. One day he receives an apple from the kindly shopkeeper, Mrs. Lundin, who asks him to mail a postcard for her. He mails the postcard, but not before he has thrown a glance at it. It is addressed to a king, and it says that his son will soon be coming home, recognized by his possession of a golden apple. Bosse looks at his apple and suddenly it turns into gold. Soon after, Bosse finds a bottle with a genie trapped inside. Upon freeing it, the genie recognises the apple and takes Bosse to another world, far, far away. Upon arriving, Bosse is told that his real name is Mio, and that he is son of the king and thus prince of the land. He finds a new best friend, Jum-Jum, and receives the horse Miramis from his father. However, he soon learns that not everything in this world is as wonderful as it first seemed. In the lands beyond that of the king lives an evil knight named Kato, whose hatred is so strong that the land around his castle is barren and singed. He has kidnapped several children from the nearby villages, and he poses a constant threat to the people living there. Mio is told that his destiny is to fight Kato, even though he is only a child. Together with Jum-Jum and Miramis, Mio sets out on a perilous journey into the land of Kato, as the stories have foreseen for thousands and thousands of years. In the American version, Mio is first called Karl Anders Nilsson, nicknamed Andy, and Jum-Jum's name is Pompoo.