Modern woman Shen Yunshu accidentally transmigrates into a book, becoming a 300-jin (150-kilogram) overweight cannon-fodder wife in the 1970s. The moment she opens her eyes, she finds herself caught up in a scandal where she is falsely accused of drugging someone to force a marriage. Gu Shixing, a key figure at the steel mill, publicly stands up for her and decides to marry her. Determined to change the original character's fate of dying tragically in childbirth due to obesity, Shen Yunshu uses modern knowledge to lose weight at a furious pace, transforming herself into a stunning beauty. With her modern knowledge, she repeatedly foils the schemes of her romantic rival, Lin Xiaoxue, while also resolving multiple crises at the steel mill involving production, quality, and funding. From a fat wife who was once scorned, she becomes a highly respected key talent throughout the entire factory. As Shen Yunshu and Gu Shixing grow closer while tackling one crisis after another together, she safely gives birth to twins—a boy and a girl—and successfully turns her fate around to rewrite the ending.