Yao Lan (played by Yu Feihong), who is over 30 years old, is the manager of a convenience store. Through a dating website, she met Tian Kun (played by Tu Songyan), who seemed to be honest and kind. The two hit it off and soon decided to get married. But at the critical moment, Yao Lan found evidence of her fiancé's infidelity and canceled the wedding in anger. At the lowest moment, Lu Xiaobei (played by Yang Jue), a young man who was watching the excitement, accidentally broke into the lives of Yao Lan and her mother (played by Xu Di), adding a lot of troubles to the mother and daughter who were full of setbacks in their emotional journey. Taking this as an opportunity, Lu Xiaobei, who was full of quirks, seemed to fall in love with Yao Lan, who was nine years older than him, so he shamelessly pursued her. Sister-brother love tests not only the age of the two, but also their attitude towards life, love and life. In the process of getting along with this "brother", Yao Lan had to face all kinds of situations that she had never imagined...