Eunuch Lan's feelings for the Crown Prince actually stem from the experiences of his past.
When Eunuch Lan was still Lan Zhengguang, disaster struck his family when he was five years old, leaving him an orphan. With no choice but to wander and beg for survival, he might have died from hunger or been killed by others if not for the eldest daughter of the Yong Family, Yunnuan, who took him in. Thus, Yunnuan rooted herself in his heart like a fairy.
Yunnuan taught him to read and even arranged for him to be trained in martial arts, and she had even personally made clothes for him.
In the succeeding years, he always served at her side as a pageboy, resolved that he was willing to do anything just to be near her for the rest of his life.
Later, when Yunnuan came of age, the late Emperor, who has since passed away, betrothed her to the Crown Prince,
Eventually, Yunnuan was conferred the title of Crown Princess Consort, and later, Empress.