After I Transmigrated into a Book, the Crown Prince Fell for Me

A pampered little heiress transmigrates into the role of a vicious female supporting character. Finding it all novel and exciting, she meets Jiang Huai, the neglected crown prince. He's guarded and cunning, while she's spoiled and chatty, constantly saying baffling, nonsensical things to him. She'll even burst into tears over the tiniest thing. At first, Jiang Huai thinks she's too delicate. Later, he decides she was always meant to be his.