Princess Yona lives an ideal life as the only princess of her kingdom. Doted on by her father, the king, and protected by her faithful guard Hak, she cherishes the time spent with the man she loves, Su-won. But everything changes on her 16th birthday when tragedy strikes her family! While on the run, Yona and Hak head to Hak's hometown where she attempts to heal her broken heart. However, she can't rest there for long once she discovers that Su-won may soon become king! What will Yona choose to do in the wake of this news?