Centuries ago, humanity's natural enemy, “Demons,” invaded the world and oppressed humankind. The Great Demon Lord and 47 subordinates known as Demon Lords have since dominated the world, while the human race lives on in fear. In desperation, a last-ditch effort for humanity's very survival is placed in the hands of 47 people gathered from across the world. These heroes will oppose the demon army and win back humanity's freedom…or die trying!