Retells the traditional Japanese tale in which a boy, who has defeated all the other boys in his village in wrestling, travels to the city to test his skill at a sumo tournament, but along the way he meets a girl who is even stronger than he.

Each generation, a competition is held to find the next empress of Honoku. The rules are simple. Survive the palace's enchanted seasonal rooms. Conquer Winter, Spring, Summer, and Fall. Marry the prince. All are eligible to compete--all except yōkai, supernatural monsters and spirits whom the human emperor is determined to enslave and destroy. Mari has spent a lifetime training to become empress. Winning should be easy. And it would be, if she weren't...

Even with the combined skills of Kage Tatsumi and the demon Hakaimono inside of him, they both know that it may be impossible to overcome the evil forces that control the cursed sword that keep them trapped as one.