Souma, a King of the smallest, yet the richest country in the world, possessed the power 'to import things' from 'another world' with 'money'. When the enemy nation invaded, he 'import' tanks and machine guns from another world and defeated the sword and arrow equipped enemy army.
He imported many things that broken the dimension and barriers of the worlds, making the country gradually become prosperous, which make citizens immigrated to the country one after another.
Since the small country didn't had enough territory for the increased population to settle, since it couldn't be helped, he expanded the country's territory and ended up reigned as the Emperor of a Grand Empire.
