Gu Nianshen and Lin Yiqian have been engaged since childhood. Due to the instigation of adoptive daughter Xi Xia, Lin Yiqian mistakenly believes that he loves someone else. During a drunken night, the two share a relationship; after becoming pregnant, she is instead rejected and has no choice but to take the child and go abroad for five years. Upon returning to the country, she agrees to a one-year contract marriage with Gu Nianshen and hides her son's identity. Unexpectedly, her son Lin Xiaoyu encounters Gu Nianshen and bluntly states that he is his son. After DNA confirmation, Gu Nianshen mistakenly believes that Lin Xiaoyu is his illegitimate child, afraid that Lin Yiqian will find out and divorce him. Amidst testing each other, the two gradually understand each other's feelings, clear up the misunderstandings created by Xi Xia, and ultimately love and stay together.