Promise for a Thousand Years

He originally had no fights with the world and had no worries. Although he was a prince, he was helplessly bound by his status and had no use for his talents. Until he met her, a princess in a barbarian land. She was destined to be violated. She was his calamity and also an opportunity. She has a proud appearance and amazing intelligence, but there is also a secret that only she knows. She comes from the future, from an unknown time and space. She can escape into reincarnation, but she cannot erase her memory. She has the same face in every life. She has to look for her only lover, but he has already forgotten her... The most painful thing is this, and the greatest loneliness is also this. I remember you, I love you deeply, but you have forgotten me.