"There's always people to be saved, at every place, at every era. So let's save them all!" In the middle of a war-torn land, a girl declared thus. She said she was the Demon Lord, the Bringer of Calamity, the Greatest of all Evils. And she extended her hand towards him, the hero, asking for his help. "Helping others is only natural for the Demon Lord, right?" Humanity and the demons cannot walk the same path. He thought it too ridiculous to believe. But perhaps, against the true cruelty of mankind... maybe they were a necessity.