Coming from a poor family in the Four Rivers of Rivers and Mountains, the impoverished top student Lin Siwang learns on the eve of the senior high school first mock exam that she is actually the wrongly swapped true heiress of the wealthy Su family in Beijing. Returning to the Su family with the pragmatic goal of optimizing her gaokao conditions using a Beijing Hukou, she instead finds her family wildly favoring the fake heiress Su Zhiyi while treating her with extreme coldness and exclusion. Facing Su Zhiyi's green tea tricks, her brothers' brainless shielding, and her parents' hypocritical guilt, Lin Siwang remains completely clear-headed, pouring all her energy into her studies with a crystal-clear goal. She resolutely chooses to live at school to escape the family chaos, achieves a stunning score of 719 on the Beijing gaokao with her rock-solid foundation, and becomes the top scorer.