To find a companion for his seven-year-old son, Lu Yanzhi, Lu Zhenting, chairman of the Lu Group, brings Su Wan to the Lu family.
Su Wan has known since childhood that she is meant to be the young heir's companion. To put her grandmother at ease, she devotes herself diligently to playing the role of a good older sister. But as they spend more time together, Lu Yanzhi grows increasingly possessive of her. For his son, Lu Zhenting makes a deal with Su Wan: after he dies, he will give her everything the Lu family owns, in exchange for her protecting Lu Yanzhi for the rest of his life as his wife.
Everyone at the wedding says Su Wan has gone from sparrow to phoenix. Only she knows the truth: she will protect Lu Yanzhi, and Chairman Lu will care for her grandmother for the rest of her life.
But when the icy young heir turns into an affectionate, devoted puppy, cooking for her late at night and comforting her after a breakup, Su Wan finally realizes that their pretend marriage has long since become real. Whether it's love, family, or friendship, from the moment she met him, her whole world has belonged to Lu Yanzhi.
