Gukon

Eunri Dam was only a child when she found Gyeol's bloody body in the river by her home in Je. Back then, she didn't know his real name was Segyeol Yiheon or that he was the crown prince of Sayuta...Je's enemy nation. Gyeol knew that Eunri was to be engaged to the crown prince of Je, but even that couldn't stop him from falling for her. Before returning to his homeland, Gyeol promised Eunri that he would marry her one day. After that...everything went up in flames.

(Source: Tapas)