The runaway angel princess and the four guardians of Heaven - who are in search of her in the human world - are on a field trip. But the princess, who is still disguised as a school boy, is plagued with more troubles as always. Will the guardians be able to save her from all the trouble?! Also, the secret past of beautiful Ah-Hin and powerful Woo-Hyun is about to be revealed. What will be waiting for them after the trip? This ridiculously funny and charming fantasy will draw you right into their world.