Afmet Oukoku Monogatari

Chery, tomboyish princess of the Afmet Kingdom is arranged by her parent 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 duty is to make the dragon fall asleep every 10 years to save their country. Chery's dad, the king is now injured and so the kingdom need to find their new king, thus the reason for Chery to have to tied the knot with some top level magician. Chery doesn't want to get married, and one day before her future husband moves in the palace, she sneaked out to go to the 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 cause her to get caught. Chery is now being restrained and now have to tack along with her favorite band to the fire dragon's lair. (Source: MU)