Fresh off their victory over the demon lord Bifrons, Makoto's party joins Princess Sophia on a political trip to broker an alliance with Great Keith. However, diplomacy quickly goes out the window when the party is attacked by Great Keith's Hero of Incandescence, who is known to be the strongest hero of them all. On top of that, Makoto soon hears rumors that one of his former classmates has been captured and sold into slavery. As the Roses delegation tries to get to the heart of the matter, they find themselves facing another one of the Snake Sect's nefarious plots. And though Makoto has thwarted them before, this time, he's at a distinct disadvantage—Great Keith, with its desert climate, has hardly any water elementals! Can Roses secure a mighty new ally? Or will both nations fall into the hands of demons?