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!

The Kai Empire begins their plans to attack the Kingdom of Kohka, with North Kai leader Ying Kuelbo particularly interested in capturing the Dragon Warriors! When Yona and Jaeha are taken to Kai Empire against their will, Hak debates the unimaginable in order to save them--joining forces with the Kohka army!