Nihonkoku Shoukan (日本国召喚) or Japan Summons

The story begins when modern-day Japan is mysteriously transported to another world by a supernatural phenomenon. The entire country, including its islands, infrastructure, population, and military, is suddenly relocated to a fantastical realm filled with medieval kingdoms, mythical creatures, and magic.

Well how about you play as other nations rather than Japan being spawned? Yes you can!

The series is often compared to other "isekai" (other-world) works like GATE: Jieitai Kanochi nite, Kaku Tatakaeri, but it differentiates itself with a stronger focus on national-level politics and modern warfare.

At this point this where you can Change the story from the Beginning