Summon Night: Twin Age is a role-playing game for the Nintendo DS, featuring protagonists Reiha and Aldo, who grew up as siblings on the tropical island of Jarazi. They can communicate with Nature Spirits, whose unusual behavior prompts them to uncover the source of the disturbance. Their journey takes them from their island home to human territories, where their intertwined fates were set in motion.
Reiha and Aldo grew up together as brother and sister on the tropical island of Jarazi, among a race of people with beast-like features. There they learned to commune with the Nature Spirits that surrounded them. One day, the Spirits began acting strangely, prompting Reiha and Aldo to investigate. Their quest to find out who or what is behind the corruption of the Spirits will lead them back to the human lands where the cataclysm first brought them together.