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! A Kai Empire soldier fatally strikes Zeno, but he doesn't die! Yona and her friends are shocked by the Yellow Dragon's power as well as what he reveals about both his past and the Crimson Dragon King...