After Mistakenly Picking Up The Villainous Male Supporting Character

Ji Yu, a modern university student, transmigrates into the body of a young woman in the Daqi Dynasty, inheriting her father's failing pharmacy, Jishitang, and a crushing debt of three hundred taels of silver owed to the wealthy merchant Du Tingsong. Du Tingsong has long coveted the pharmacy's prime location and threatens to force Ji Yu into marriage with his simple-minded son, Du Cong, if the debt is not repaid. The story opens with Du Cong's housekeeper, Huang Quan, violently ransacking the pharmacy and destroying precious medicinal ingredients. Ji Yu cleverly bluff that a crushed herb was a thousand-year-old treasure to negotiate a one-month extension on her debt, buying herself time to find a solution.

Remembering the plot of the novel she read before transmigrating, Ji Yu learns that the Third Prince, Qi Yu, is the second male lead who will soon be assassinated and drift downstream to her city. According to the story, a village girl will rescue him and receive a reward of one hundred taels of gold and a grand residence. Determined to secure her future, Ji Yu waits by the river and successfully rescues the severely wounded prince before the original village girl can find him. She smuggles him into her home hidden in a sanitation cart, hiding him in her late father's room while she treats his critical arrow wound and poison.

Qi Yu, known in this narrative as Nan Xing, is initially suspicious and hostile, viewing Ji Yu with wariness due to his traumatic experience. Ji Yu, however, is focused solely on the financial reward, treating him with excessive attentiveness that confuses him. Complications arise when Ji Yu discovers that Nan Xing is suffering from severe allergic reactions to various foods, causing him to collapse repeatedly. She later realizes these are not allergies but symptoms of poisoning from the local well water, which has been contaminated. After treating the water supply and saving her neighbor's grandson from the same poison, she gains Nan Xing's trust by explaining the situation and proving her medical competence.

While nursing Nan Xing back to health, Ji Yu encounters another crisis involving Du Cong. She witnesses an old man, Liu, being falsely accused by a merchant of poisoning his goose, a scheme to extort money. Ji Yu exposes the old man's fraud but soon learns the deeper tragedy: the old man's granddaughter was abducted and assaulted by Du Cong. Ji Yu visits the victim, Yun'er, and provides medical treatment, discovering the extent of her injuries. She comforts the grieving family but warns them that the local authorities are corrupt due to Du Tingsong's sister being the Prefect's favorite concubine, making legal recourse impossible.

Ji Yu confides in Nan Xing about the injustice suffered by Yun'er, hoping to leverage his status as a royal prince to seek justice. Nan Xing is moved by her compassion and the brutality of Du Cong's actions. As Ji Yu continues to care for him, the dynamic between them shifts from mere transaction to a complex relationship built on mutual respect and hidden vulnerabilities. Ji Yu remains unaware that her actions are altering the original plot, and Nan Xing begins to question his fate and his growing feelings for the clever, kind-hearted woman who saved his life.

The narrative sets the stage for Ji Yu to use her medical skills and knowledge of the future to not only pay off her debts but also to challenge the corrupt power of the Du family. With Nan Xing's support, she plans to expose Du Cong's crimes and protect the innocent, transforming her role from a desperate debtor to an active agent of change in a world that initially sought to crush her.