The story starts with the sudden death of the Crown Princess of Joseon. Crown Prince Lee Gak and his fellows investigate the truth of her death, but they end up falling onto Park Ha's rooftop house in the 21st century. That is how Lee Gak and Park Ha, the lead characters, meet in the drama. In the meantime, an heir to a conglomerate goes missing in New York. And his cousin Tae Mu who has a secret affair with his secretary Se Na becomes a strong candidate for the successor to the company. As the story develops, the four main characters' relationships get more complicated. Rooftop Prince seems to be a cliche that contains feelings of love, jealousy, and ambition. However, as the time-traveling is added, the way the drama portraits the story is quite fresh.