Goong manga

Goong summary:

From Yen Press: Monarchy ended long ago in Korea, but there are still other countries with Kings, Queens, princes and princesses. What if Korea had continued monarchism? What if all the beautiful palaces which are now only historical relics were actually filled with people? What if the glamorous royal family still maintained the palace customs? Welcome to a world where Korea still has the royal family living their lives! But for Chae-Kyung, a high-school girl, this is a tragedy, since she has to marry the prince who turns out to be a total jerk! Because of a promise between their grandfathers, Chae-Kyung must marry Shin, the crown prince of Korea. Though they each have their reasons for agreeing to marry, they find themselves falling deeply in love, even as others attempt to drive them apart.