Lin Zhizhi, a young woman who died in a car accident in her original world, transmigrates into the body of a novel character with the same name. The novel, titled Those Years of Secret Love, follows the female protagonist Song Nuan and her unrequited love for the male lead, Lu Yi. In the original story, the original Lin Zhizhi is the male lead's ex-girlfriend who appears with a child, ruins the female lead's chances, and ultimately dies alone abroad. Upon transmigration, Lin Zhizhi discovers she is pregnant with Lu Yi's child and receives a mechanical voice informing her that she must give birth to the child and ensure his happy upbringing to survive in this new world. The original Lin Zhizhi has been sent to another world, and from this point forward, the transmigrated Lin Zhizhi is the sole occupant of the body.
Rather than stepping aside for the original female lead, Lin Zhizhi decides to take initiative. She and Lu Yi had become entangled the night before after both were drunk, an event the original Lin Zhizhi had used to maintain her status as his girlfriend. Lu Yi had initially claimed her as his girlfriend to protect her from his aggressive half-brother, Lu Tian, with the intention of breaking up after they entered university. Lin Zhizhi proposes a two-month trial relationship: if they do not develop genuine feelings for each other, they will part ways amicably. Lu Yi agrees, and their relationship begins to evolve as they spend more time together. Lin Zhizhi, aware of the novel's plot, also learns that she is the sole heir to the wealthy Lin Corporation, a company that will later face bankruptcy due to betrayal by key employees.
Lin Zhizhi visits the company and meets Secretary Zhang, a loyal employee who served her parents for years. Remembering the plot, she knows Secretary Zhang will eventually betray the company, but she suspects there are underlying reasons tied to his family. During a dinner with Lu Yi and his roommates, where Song Nuan attempts to reconnect with Lu Yi, Lin Zhizhi asserts her presence confidently, shocking Song Nuan and her roommates. She also discovers that Section Chief Liu from the Marketing Department is conspiring with an unknown masked figure to undermine the company, and that Secretary Zhang's daughter is seriously ill, which may be the leverage used to corrupt him. Lin Zhizhi resolves to prevent the betrayal by addressing Secretary Zhang's family crisis and gathering evidence against Section Chief Liu.
As her relationship with Lu Yi deepens, Lin Zhizhi visits his university classes and joins him on outings. Lu Yi, initially reserved and aloof, begins to show warmth and protectiveness toward her. Their bond strengthens through shared moments, including a kiss at her apartment complex that leaves both of them emotionally invested. Lin Zhizhi, now fully committed to this life and her unborn child, navigates the challenges of managing a corporate empire while balancing her relationship with Lu Yi and countering the hidden threats within her company. The story follows her efforts to rewrite her fate, protect her family, and build a genuine future with the man she has come to love, all while staying ahead of the plot's original tragic trajectory.
