The Island of the Ilus is the place where the animals stay before they come to the world. There they all begin in the form of an Ilú, a small ethereal and happy being. After a while they go to the House of Delivery to embark for terrestrial life in the form of some animal. Problems happen when some are changed at the time of boarding. The family receives the wrong animal and does not accept it, forcing the puppy to return to the Island. This is the case of Pocó, who is rejected and returns disappointed. But he ends up meeting a clan he never imagined existed.