Adapted from the light and dark novel "Hidden Marriage in the Office". Tu Xiaoning, the lobby manager who works on the first floor of Huayuan Building, is in the critical period of becoming a regular employee. Ji Yuheng, a young talent who works on the 17th floor of the building, is a business backbone who is in the limelight. They have a common need to get married as soon as possible, and the two parallel lines intersect. In Tu Xiaoning's eyes, Ji Yuheng is a marriage partner that far exceeds expectations, and in Ji Yuheng's eyes, the young Tu Xiaoning is the light that once illuminated him, and marrying Tu Xiaoning is his only firm choice. Just when the two had the courage to establish a marriage relationship, Ji Yuheng suddenly became Tu Xiaoning's boss. This pair of childhood classmates ten years ago, by accident, have a dual relationship of colleagues and newlyweds ten years later. They work together to explore the mysteries of marriage and life.