Adventures of Little Herbert in Mushroomland

Herbert is a small and shy boy that wants to learn how to play baseball to fit in with his piers. By magical transformation he ends up in Mushroomland and a size of a mushroom. He is saved by a mushroom boy who takes him to his town and lets him stay with his family. In the course of his adventure Herbert not only learns how to play baseball, but he defeats his new friends and their land form a giant Slug, thus becoming a hero of Mushroomland and a different person.