Yuji travels to a town known for its monster-enhancing armor, Boginia. A gigantic Fire Dragon has shown up from the volcano next to the town. Although it usually withdraws into the volcano after a bit of time, it unfortunately shows up just as it starts to rain, which angers it enough to make it charge toward the town. Employing the powers of his monster armor-enhanced slimes and Pride Wolf, Yuji challenges the powerful and gigantic dragon!