Eight hundred years ago, the great war against the Demon King ended thanks to the sacrifice of the legendary hero who disappeared with the Demon King to somewhere unknown. However, the world did not become a better place. Humans instead waged war against one another for greed and power, which eventually gave rise to a new order of heroes in the modern era called HEERO.
In a remote village named Kiel Village, lived Reika Argan, a 7-year-old boy who dreamed of becoming a Heero. Reika lived a simple life with his mother, Selia Argan, who worked as the head maid at the noble Barley estate. Reika never knew that his mother was actually a great former Heero who chose to retire in order to raise him.
A terrible tragedy struck when Kiel Village was suddenly attacked by a legendary monster, the Hydra. To protect Reika, Selia died miserably right in front of her own child's eyes. Shattered by grief and rage, Reika's hidden power awakened unexpectedly—five (Soul Stars) instantly shone on his back, an extraordinary potential that was impossible for a child his age to possess. Reika successfully slaughtered the Hydra brutally in an unconscious state.
To protect Reika from greedy factions targeting his power, Wiz (the youngest Heero) and Xion Barley (the leader of Kiel Village) agreed to keep the incident a secret and hide Reika's identity. They lied to the world and even to Reika himself, claiming that Wiz was the one who killed the Hydra.
Five years passed. Reika had now grown into a teenager and mastered ice magic. When his childhood friend left to go to school in the capital, Reika received a surprise: an application form to the Heero Academy.
Reika then stepped forward, leaving his village behind to pursue his dream of becoming a Heero and to catch up with his childhood friend, Alisa Barley. However, Reika was unaware that out there, a mysterious pair of eyes from the past was watching him, ready to hunt down the legendary owner of the five stars.