The story takes place on the continent Knights during a period of 1229 years (til now). Knights is split into seven equal districts named after the seven magical elements. Also, it is divided into the two kingdoms of magicians and demons.
In the year 1121, the “great catastrophe” caused the magical pillars of Knights to shatter and a lot of people lost their powers til 60-80 years later the magical energy starts to regenerate. Meanwhile, both kingdoms agreed on a 100-year peace contract.
Archdemon Iaris, who was involved in the great catastrophe, was finally slain in 1210 and the half-demon Seras claimed his throne. Now the new demon lord has only one goal: destroy the only person who could interfere with an upcoming war, the child of Iaris’ slayer.