There was an urban legend that there was a legendary, undefeated gamer called [ ], but in reality he was just a NEET brother and sister called 空 (Sora) and 白 (Shiro). These hikikomori siblings who both refer to the real world as a worthless "Kuso Game" are one day summoned to a different world by a boy calling himself "God". In this world, war is prohibited by God and everything is instead decided by a game...that's right, even country borders. Can the two NEET brother and sister save the last of the human race , which only has one city left?
"Now...let the game begin!"