Azure Dreams is set in a town called Monsbaiya. Located in the desert, the town prospers only because of the Monster Tower looming over it. In this town lives a skilled and famous monster tamer named Guy. On a stormy day, Guy disappears in the tower, never to be seen again. Ever since he disappeared, Guy's family has struggled to get by, putting all their hopes on Koh, his son, who will be allowed to enter the tower when he turns 15. When Koh finally reaches adulthood, he meets a vagabond familiar named Kewne, a monster that can speak the human language. Kewne and Koh then embark on a quest to reach the top floor of the Monster Tower and find out the truth about Guy's fate.