Kugutsu Senki

A world divided into nine countries by nine volcanoes and rivers. Repeated eruptions and flooding rivers containing mineral poisons. In such a barren land, people are waiting for the appearance of the "Taiju-ou" who is said to be responsible for the well-being of a country. The two candidates are the "King's Vessel", which was selected as the "Sacred Treasure". One becomes a king, and one dedicates his life to the king.

A strange fate that unfolds in a common world.

(Source: Kodansha, translated)