Gu Changan is the eldest son of the Zhenbei Hou Mansion, because the Holy Father granted marriage to his sister and the old prime minister's only son Wen Lianyun.
The Prime Minister came to have a son in his old age, but Wen Lian Yun was born with an innate frailty. He was frail and sick since he was a child and was told by a fortune teller that he would not survive. However, he was already 19 this year and his illness became even more serious. The Prime Minister, a veteran of two dynasties, cried until he was unconscious.
His sister didn't want to marry him and become a widow in the future, so the foolish Gu Changan got married for her.
But that fortune teller has real skills
Gu Changan x Wen Lianyun
Hot-faced fool attack/gentle, sick and weak person
Intention: A person who does not understand what love is, understands love in another incomplete soul