Hamel the violinist, Raiel the pianist, Flute the magess, and Sizer the female warrior were on a quest to stop the Demon King. During their journey, they stopped in a small kingdom and killed a rampaging monster. The king and queen were grateful and asked for their help in rescuing their daughter, who had been abducted by a monster in a nearby fortress. The group agreed to launch a rescue mission and defeat the monster. However, the fortress was heavily fortified, posing a formidable challenge.