Hanni Pham was known to those around her to be an introverted, studious, and a career driven person. All her life, she knew only of studying and working hard to climb the ranks of the competitive healthcare field. When Hanni lands a new job position as an ER nurse at one of the most prestigious hospitals in Seoul, life starts to become more complicated for her. Minji, the head surgeon of the ER is strangely self reserved, cold and strict. When the news of Hanni working to become the next ER surgeon reaches the ears of Minji, things start to spiral out of control.