Childhood Groom (Book Transmigration)

Meng Xingyan discovers that he has transmigrated into a book. But by the time he figures it out, he has already lived in this world for twenty years, and raised his wife from a little girl with his own hands. Then he is told that his wife belongs to someone else?! How is he supposed to put up with that? What? His adorable little Niannian is also a villainous boss who burns herself to death in the end?! Meng Xingyan is done putting up with it. Theme: Study hard and improve every day.