In Eternal Nations, a fantasy strategy game where players manage an empire, Takuto Ira is a legendary player who sits atop the leaderboard. Takuto goes unconscious during a hospitalization and awakens on the continent of Idoragya, which looks just like the game. Takuto meets Sludge Atou, his favorite unit in the game, and decides to build Mynoghra, an evil empire, in this isekai apocalypse anime.