How a Realist Hero Rebuilt the Kingdom Novel Volume 15 was written by Dojyomaru with illustrations by Fuyuyuki.

Following the political fracture, the three great powers are locked in fierce competition. When the haughty high elves of the Spirit Kingdom of Garlan come asking for help in reclaiming their land, King Souma refuses, and it is the Great Tiger Kingdom that deploys troops to aid them. But the Spirit Kingdom is plagued by a curse, a deadly disease that claims the soldiers’ lives and could threaten the entire world. Souma will have to merge his modern knowledge with the magic and medicine of this fantasy world in order to stop the spread!