Gamer siblings Sora and Shiro, having already secured the future of the human nation of Elkia in a world where every conflict is settled by games, set their sights on the Eastern Union, the third-ranked power in that world. This manga adapts the Eastern Union arc of the original light novels, following the pair as they scheme and gamble their way past the setting's other sentient races while pushing their unbeaten streak further, betting bigger than ever on games only they seem able to win.