Archaeology student Lee Seol (Kim Tae-hee) was just an ordinary student yesterday, but when she woke up one night, she became a princess of the Korean royal family! Frugal life was replaced by luxurious clothes and delicious food; textbook knowledge was replaced by various social etiquette. This is not a dream, but Lee Seol's real life. The great changes that seem worthy of envy to outsiders are all kinds of discomfort to Lee Seol. The one who bothers her most is her tutor Park Hae-young (Song Seung-heon). The only heir to the most powerful chaebol in the Republic of Korea, he is also a Korean diplomat and looks very handsome. With such a tutor, Lee Seol has undoubtedly become the object of jealousy of thousands of Korean women. But in Lee Seol's eyes, Park Hae-young is just a demon king sent by God to torture her. The two get along with each other full of friction, and Lee Seol and Hae-young, who dislike each other, fall in love with each other over time. But the road to happiness is never smooth, but the prince will eventually hold the princess' hand and live happily ever after.