She is the adopted daughter of the Brown family, living under someone else's roof. He is the lofty heir to the Brown family. They are step-siblings in name, yet they harbor a hidden affection that has spanned years. The family arranges a business marriage for her, but he insists on intervening, making her his secretary, forcing her to call off the engagement, and clutching her wrist late at night to say, "There are the mistakes we made together." From the forbidden entanglement in the Hcity villa to fleeing side by side on the streets of New York, they defy family opposition and societal judgment, turning their 'mistaken' love into their only redemption. In this immoral descent, he says, "Don't be afraid. I'll stand in front of you." And she has long been certain: Some mistakes, she is willing to make with him; Some people, she never wants to let go of for the rest of her life.