Yona of the Dawn. Volume 3: Mizuho Kusanagi

A red-haired princess loses her family and her kingdom… Now she must rise and fight for her throne!
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!
Yona and Hak set out on a journey to find a priest who can see the future. After they get severely injured falling from a cliff, a boy named Yun and his guardian Ik-su nurse them back to health—and Ik-su happens to be a priest! When Yona tells him that she wishes to protect the lives of those who are precious to her, what path will Ik-su show her?