After discovering her classmate Prince Sieghart is secretly a woman, Mercedes finds herself at the center of a shadowy struggle for the throne. Sieghart claims to be a body double, but is that the whole truth? Having no one else to turn to, Mercedes reaches out to her father, and they soon realize Sieghart is none other than the long-lost Princess Sieglinde, the last inheritor of the Royal Sword. Together, they resolve to oust the fake king and return power to the rightful heir.
