Back in Ancient Times, My Childhood Betrothed Won't Leave Me Alone

[A possessive, calculating woman x a man of mysterious origins who is hopelessly devoted to his wife]

The modern orphan Yin Hanguang is drawn by a mysterious force to transmigrate to ancient times. After witnessing the royal family persecute the Duke of Zhenguo's household, she switches identities with the young lady of the house and takes her place caring for the family. She is surprised to discover that the original owner's hidden guard is actually the childhood betrothed her birth parents raised in their home, who has waited ten years for her. His identity is unknown, and he may be a member of the royal family.

Chixiao (mumbling in his sleep): My lady, Hanguang is mine.

Hanguang: Good boy. That's how it should be. Even in your dreams, you can't be without me.