In the realm of Disboard, ruled by the supreme deity Tet, sixteen sentient races coexist. Among them, humanity, known as Imanity, stands as the weakest due to their lack of magical powers. In this world, every dispute is resolved through games, leaving humans with seemingly no hope. However, their fate shifts when two strangers suddenly arrive.
On Earth, step-siblings Sora and Shiro live as reclusive gaming prodigies known by the alias "Blank." Unbeatable in every online game they encounter, they view life as a tedious pastime until a mysterious message transports them to Disboard. Tet, the sender of the message, outlines the strict laws of this new world before vanishing, forcing Sora and Shiro to navigate their unfamiliar surroundings. They eventually find shelter in Elkia, the last surviving human kingdom.
There, they encounter Stephanie Dola, a spirited young woman determined to reclaim the throne she believes is her father's rightful inheritance. Her impulsive nature, however, hinders her success. Recognizing her resolve, Sora and Shiro choose to aid Stephanie in restoring Elkia, with their ultimate ambition being to seize control of this enigmatic world.