With Souma's defeat of the giant monster that menaced the Nine-Headed Dragon Archipelago, the people of the Kingdom celebrate his achievement. However, as far as the rest of the world is concerned, someone else has done something even greater—reclaim a piece of the Demon Lord's Domain. That is what Fuuga, King of Malmkhitan, has accomplished.

Within the Union of Eastern Nations, Fuuga's power and influence rapidly expand. Unable to accept this encroachment, the anti-Fuuga faction launches an unsuccessful attempt on his life. This sparks all the nations of the Union to be drawn into a massive conflagration?! When this conflict ends, the world will move on to a new stage.