When an unexpected ambush during a school trip sends Shōichirō and his classmates into the land of the dead, they are thrust into a fierce struggle between the gods and their warriors. The mysterious forces of Hades have already begun their assault, and Shōichirō's destiny is forever altered. But he's not alone--Cattleya, the reincarnation of Athena herself, fights to defend the living, as shocking truths about a darker conspiracy threaten everything they know.