The emperor of the Phoenix Empire, who is known as a great and powerful emperor, the Heavenly Emperor, Shouko. Kouhi, who was born and raised by a proud female warrior, Empress Rei, a member of the Female Crown Tribe, lived her life with the goal of becoming an emperor in the future. Kouhi was given the right to succeed to the throne in accordance with Emperor Shouko the Great's intention to make his own son an equal candidate for succession, but there is no precedent for a woman to sit on the throne in the Phoenix Empire. While many of her old-fashioned subjects supported the brothers, believing that "women are not allowed to participate in politics," Kouhi spent her days training to develop "kingly qualities" that would make her a better emperor than anyone else. Then one day, an incident that will greatly change the fate of Phoenix Country and Kouhi occurred!? The grand founding story of the Warrior Princess begins!