Afmet Oukoku Monogatari

A tomboyish princess from the Afmet Kingdom is forced into an arranged marriage to secure a new king, as the kingdom requires its ruler to be a high-level magician capable of calming a fire dragon that awakens every ten years. With her father, the current king, injured, the princess resists the marriage and sneaks out to attend a concert the night before her future husband arrives. During the event, she enters the band’s dressing room and overhears them talking about the fire dragon. Startled, she is caught and taken captive. She is then forced to accompany the band on their journey to the dragon’s lair.