On the day that surgeon Xia Mu and her boyfriend of three years, Chai Heng, agreed to register their marriage, Chai Heng stood her up on the grounds that his childhood sweetheart Lu Xueer was sick. Waiting at the civil affairs bureau alone for hours, she accidentally bumped into Cheng Qingyan, the CEO of the Cheng Group who was being pressured by his family to marry. On an impulse, Xia Mu proposed registering their marriage, Cheng Qingyan agreed, and the two strangers registered their marriage on the very day they met. From her initial trepidation and impulse, Xia Mu was gradually touched by Cheng Qingyan's sincerity as they spent time together. Moving from polite detachment to a growing ambiguity, their interactions became sweet and natural, and their marital relationship slowly shifted from a formal contract to a mutual true heart.