How A Realist Hero Rebuilt The Kingdom Vol. 15 (Light Novel)

In Vol. 15, the world has entered an era of conflict between the three major powers: the Great Tiger Kingdom of Haan, the Gran Chaos Empire, and the Maritime Alliance, of which the Kingdom of Friedonia is an ally. Suddenly, the Spirit Kingdom of Garlan, a nation of high elves, contacts the three major powers. Their goal is to reclaim the territory they lost due to the expansion of the Demon Lord’s Domain. Seeing no merit in it, Kazuya refuses their request for aid, but the Great Tiger Kingdom agrees to the request and dispatches an army. However, the situation turns strange when healthy soldiers begin collapsing one after another. It turns out there is a deadly disease called the Curse of the Spirit King, and it’s spreading throughout the Spirit Kingdom! Kazuya comes up with an unprecedented plan to deal with the disease, but will it be enough?
Notice: This book is written in Japanese.