The heirs of the Kou Empire's throne gather to mourn their deceased father and decide his successor. In the occasion, Hakuei reminisces how ruthless her brother Hakuryuu has become after obtaining Zagan and becoming a general like her, although his army is solely composed of monsters he subdued. There is little doubt that their older brother Kouen will be chosen as the new emperor. However, their mother and empress Gyokuen Ren is appointed as the next ruler instead by a will allegedly left by her late husband, and a divide is created among the royal court, although Gyokuen claims that she will eventually relinquish the throne to Kouen once their ambition to conquer the whole world has been fulfilled...