Daiteikoku

Before the United Space Age of 0 AD, humanity was scattered across vast star regions, each forming independent nations. Travel between star systems took centuries, making contact nearly impossible. In 0 AD, the Eris Empire advanced research on 'anomalous spaces within star regions,' discovering instant travel via warp gates. This ushered in the Age of Discovery, as ambitious humans repainted the galactic map through conquest and submission. By 939 AD, three great nations prepared for war: the Eris Empire, the largest, enacted a world management plan to suppress chaos; the Japanese Empire, oldest and war-weary from conflict with the Chinese Empire, became a target. A global war was ignited.