It tells the story of a group of penguins that suddenly appeared in a small town far from the sea during an ordinary and boring summer. After witnessing a Coke can thrown by a dentist turning into a penguin, the curious boy Aoyama decided to find out what happened and embarked on an incredible and unforgettable summer adventure. This film is adapted from the novel of the same name by the famous Japanese writer Morimi Tomihiko.