Sora and Shiro, a brother and sister whose reputations as brilliant NEET (Not in Education, Employment, or Training) hikikomori (shut-in) gamers have spawned urban legends all over the internet. These two gamers even consider the real world as just another crappy game. One day, they are summoned by a boy named Teto to an alternate world, where he is the god. There, Teto has prohibited war and declared this to be a world where everything is decided by games — even national borders. Humanity has been driven back into one remaining city by the other races. Will Sora and Shiro, the good-for-nothing brother and sister, become the Saviours of Humanity on this alternate world?