Ahmet Oukoku Monogatari

Chery, tomboyish princess of the Afmet Kingdom is arranged by her parents to get married. The reason is that there's a fire dragon in their country that wakes up every 10 years. It's the country regulation to have a king which must also be a top level magician to rule there, and one of the king's duties is to make the dragon fall asleep to save their country. Chery doesn't want to get married, and one day before her future husband moves in the palace, she sneaks out to go to a concert instead. After the performance, she secretly sneaked into the band's dressing room and overheard her favorite duo discussing about the fire dragon and is startled, which causes her to get caught. Chery is now being restrained and now has to tack along with her favorite band to the fire dragon's lair.