Lightning Legend: Daigo no Daibouken

The setting takes place in the Japan-inspired Kingdom of Japone, where, around 450 years before the story starts, the Demon King Dragless rampaged through the lands until a young hero defeated and sealed him away.

After centuries of slumber, Dragless is now showing signs of awakening, and it's now up to the 14-years old Daigo Raioh, descendant of the young hero, to defeat the monster once and for all.