The adventures of a Demon King who awakens 500 years after his defeat in a futuristic world.

After the great war ended with humanity's victory, the world suddenly gets "overwritten" right before the eyes of a boy named Kai.

Haruka Sakura has no interest in weaklings, only the strongest fighters. Starting at Furin High, a school known for student brawlers who protect their town, Haruka seeks to battle his way to the top.