The background of this article is in the countryside in the 1990s. Lin Ran, who was adopted since childhood, spent all the family savings due to a serious illness of his mother, resulting in the family having no gift money to marry his brother Lin Yang, who was about to get married. So Mother Lin, who loved her son very much, promised her daughter to her son before she died. One is the younger sister whom he has watched since childhood, and the other is the older brother who loves him. The brother and sister suddenly become husband and wife. How should the two switch roles, overcome various obstacles, and live their small lives...