In the distant future, in a remote corner of Siberia, people reside in domed cities known as Domepolises. These serve as the primary human habitats on Earth, which had become uninhabitable years prior due to environmental destruction. Now, parts of the Earth are becoming habitable once more. Large sections of the Domepolises are breaking away to escape the powers that control the domes and trade. Gainer Sanga, a video game champion celebrating his 200th victory, becomes an unwilling participant in his hometown's Exodus after being wrongfully arrested by the Siberian Railway. He pilots a giant mecha, which he names 'King Gainer' after his own video game handle. He is challenged to fight other Overmen as Yapan attempts to escape across Siberia.