Li Zhiyi has a brother named Jin Yue, who is his fiancé.
Why is the elder brother his fiancé? Because the rain that summer was too heavy and his family was scattered. The Jin family felt sorry for him and adopted him as a child bride.
His brother told him that I am your brother first, I love you, and only then can you be my fiancé.
There is no blood relationship between the two protagonists. If there must be a relationship, it is only a sponsorship relationship.
World-weary brother X energetic brother