With you for thirteen years

Hai Rui (Female Lead): Gentle and affectionate, university professor teaching ancient literature and the history of ancient literature, a spinster, a goddess in most people’s eyes. Chu Chengyu (Male Lead): A cool elite, capital god, cold and hard to approach, but actually longing for the warmth of a family. Black cat Dong Dong (Real? Male Lead): The poor stray cat that was picked up by the female lead (actually the male lead), the whole body jet black, amber eyes, usually cold, in fact becoming dull and cute in a second after being teased. Really really love you. Really wish to be together with you forever. But there’s no helping it, reborn as a cat, in the end can only—— Be with you for thirteen years. All knowledge of raising a cat is the author’s nonsense, some believable and some not, please identify yourself.