At 19, Kazuya Souma was suddenly left without family after the passing of his grandfather. However, he is soon transported to Elfrieden Kingdom - a kingdom in another realm that is facing a great challenge against the demonic army. Despite being summoned as a mere offering, Kazuya determines to do more than fulfill his role as a tribute. He instead chooses to help revive the kingdom's struggling economy through administrative reform instead of embarking on adventures or warfare. Eventually, he unexpectedly becomes the King of Elfrieden and even engaged to the princess. With the help of a group of skilled individuals, he takes on the bureaucracy and works hard to rejuvenate the nation, earning the title of the "Realist Hero."