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, Soo-won. But everything changes on her 16th birthday when she witnesses her father's murder! Yona reels from the shock of losing her father and having to fight for her life. With Hak's help, she flees the castle and struggles to survive while evading her enemy's forces. But where will this displaced princess go with such an uncertain path before her?