Two worlds exist, unaware of the other's existence. These worlds survive by competing for the use of mana. The most important beings in these worlds are known as the Chosen. These Chosen must go on a journey to awaken the sleeping Summon Spirits, defeat the Desians, and restore the mana. Lloyd Irving and his friends Colette Brunel, the Chosen of Sylvarant, and Genis Sage, the smartest kid in Iselia, set off on a journey with Kratos, a mysterious mercenary and Raine, Genis' sister. Along the way, they make more friends and discover the truth behind the World Regeneration.