Yona of the Dawn Vol. 21 (manga)

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!
When Su-won hears of Riri's abduction, he launches surprise attacks on Sei fortresses in an attempt to save her. Meanwhile, Riri leaves Yona in a forest in order to lure Sei troops away from her. Will Riri escape capture and execution?