As the 13th Imperial Prince and the last in line to the throne, Kilad was happy to live outside the palace as Captain of the Imperial Border Guards. With his childhood friend Alkina, Kilad had made it his life's mission to defend the World Tree that grows in Noble, a territory of the Drakuntus Empire. However, Kilad's life takes an unexpected turn when his older brother, Elliott, is assassinated. To everyone's surprise, Elliott had named Kilad as his successor to the Drakuntus throne. The 13th Imperial Prince must now lead the empire while protecting his life and the lives of those he holds dear.