In the last season, with her bold and capable style and amazing medical skills, the surgeon Daimon Michiko (played by Ryoko Yonekura), known as "Doctor X", turned the tide in the Teito Medical University Third Hospital, which had long been like a stinking quagmire, and set off an unprecedented storm. Because of the risk of operating on a broken horse at the Hokkaido racecourse, Michiko was appreciated by the internal medicine expert Ma Yuanyi (played by Yoshiko Mita), and was invited to enter the palace of the top doctors in Japan - Teito Medical University Hospital! Not long ago, the chief surgeon Hiruma Shigemori (played by Toshiyuki Nishida) personally performed a high-risk operation for the hospital's big money-maker, a real estate tycoon Ninomiya Kin'ya (played by Nori Terada), who knew that Ninomiya's cancer recurred and was hospitalized again. The director of the second surgery department, Ebina (played by Kenichi Endo), actively prepared with his team to cooperate with Hiruma to welcome a new round of operations. The internal medicine department led by Ma Yuan had serious differences and conflicts with the surgery department in terms of treatment methods. Unknown's arrival undoubtedly intensified the conflict between the two sides...