Ten years ago, the parents of Shinsato Katsuro were brutally killed by an army of demons known as Shifters. Now, at sixteen, Katsuro is determined to enter the Celestial Military Academy, begin training for the war effort and ultimately save humanity from this perpetual, brutal conflict between humans and Shifters.

With many different islands, cultures and factions to explore, Katsuro will have to work his hardest to unlock the truths behind the Runic stones, the Duobeast system and the Condemned Children, a special group of humans marked by the Prince of the Shifters before his mysterious disappearance.

Studying hard and working out every day for years, Shinsato and his childhood best friend Naomi are finally prepared to set off on their sacred mission.