After falling under a spell, the prince's head has morphed into that of an eagle, causing him injury. While searching for a haven, he stumbles upon a church where Elle, a brave orphan, willingly takes up the task of nursing him back to wellness. As he nears his 20th birthday, Rei, now known as the Eagle Prince, must figure out a plan to revert his body back to its former state to rightfully ascend to the throne.