Long ago, the world was on the brink of destruction at the hands of the dreaded demon Abyss. However, the gods who lived on the moon resurrected the legendary "Heroine", whose powers are beyond human, and with the help of other illustrious heroes, they sealed the Abyss within the earth.

Nearly a thousand years have passed since the battle, and the sealed Demon of the Abyss once again begins to spiral out of control and burst to the surface. The world is once again engulfed in chaos.

At this time, an ordinary young man living in the remote village of Windmill manages to summon the heroine, Joan of Arc, with the help of his father's artifact.

Thanks to this encounter, the young man's destiny has changed dramatically.