After transmigrating into the body of the villainous female supporting character, I became the female lead's mouth double.

College student Jiang Yu transmigrates into a novel as the villainous supporting character Jiang Yu, also named Jiang Yu. Knowing the villainous character's tragic end, Jiang Yu decides to help her reform. Jiang Yu's husband, Lu Wenjing, doesn't believe his wife has truly changed. However, through Jiang Yu's actions, he discovers the evil Jiang Yu has genuinely improved, leading to a marriage of convenience that blossoms into love. Their son, Lu Xiaobai, is also shocked to discover that his mother, who used to ignore him, has changed and now dotes on him. Lu Xiaobai experiences unprecedented happiness and wants to live with his parents forever.