Yonghansonyeo

As the daughter of the Dragon King, Kim Yong Man has never had true independence. When her father tries to force her hand in marriage, Yong Man runs away from home, deciding to try and live a "normal" life. She enrolls in a human high school and vows to become the top student there. However, Shim Hae Soo, the current first-ranked student, isn't pleased with the appearance of a new rival, and promises himself that he'll never let her beat him. As Yong Man and Hae Soo continue to clash at school and try to busy themselves with their studies, they somehow keep getting tangled up with each other. Will these academic opponents end up falling in love – and what could this mean for Yong Man's supernatural side? This animated series was adapted from the web comic of the same name by Olso.

(Source: Rakuten Wiki)