The main plot of "What's Wrong with Secretary Kim?" revolves around Kim Mi-so, a highly competent secretary who suddenly decides to resign after working for nine years for her boss, Lee Young-joon. The central question is why she wants to quit such a stable and well-paying job, which shocks her boss who is used to relying on her heavily

. As the story unfolds, it is revealed that Mi-so’s decision to leave is tied to her desire to confront and recover lost childhood memories, particularly involving a traumatic kidnapping incident where she was protected by Lee Young-joon's brother. This past trauma and her need to understand it better form a significant emotional core of the series

. Throughout the series, tension arises from the boss’s jealousy and his struggle with guilt over his brother’s kidnapping, which complicates their relationship. Mi-so’s boss initially reacts with jealousy and some misunderstanding but eventually accepts her need to explore her past and supports her through this journey of rediscovery

. In summary, what is "wrong" with Secretary Kim is not a flaw or problem but rather her unresolved past trauma and her wish to move on from her long-term job to find personal healing and growth. The series explores their evolving relationship as they navigate these issues together