Yu Lin is a prince who disguises himself as a man and enters the enemy's country as a hostage. He looks cold and forbearing, but is tough and gentle on the inside. He is used to carrying everything alone. He is willing to sacrifice himself to protect his motherland and his sister.
Feng Beiwang is the son of a powerful official of an enemy country and a young general. He appears to be cold and stern, but in reality he values love and justice. Once he is tempted, he will remain loyal until death. He thinks he has a broken sleeve. After a painful struggle, he accepts it calmly and finally discovers that she is a woman.
Xiao Yan, the prince of an enemy country, has a deep city, is good at calculations, and is used to treating people as chess pieces. When he realizes that he is sincere, it is too late.
Yu Yao is Yu Lin's biological sister and the princess of her motherland. She is too well protected and naive and willful.
