Humans once lived as if Earth were the center of the universe. Some people embraced religion and believed that God would deliver them from suffering. After humanity was enslaved by aliens, no one spoke of God any longer. Now the grim truth is that humans are mere property of aliens. Recently, entering pet humans into the entertainment industry has become popular, and the biggest, most thrilling spectacle is known as Alien Stage. In this reality singing competition, alien sponsors flaunt their investments, while human contestants must battle to survive. No matter the relationship between opponents—whether it is love, hate, or something more extreme—only one victor can emerge each round.