As an aspiring neurosurgeon, Taeyeon is dead set into getting the grant for her research. That is, until Jessica, heiress of the Jung Foundation, enters the hospital with the intent of approving proposals. A night of one-sided rum-indulging and misunderstandings later, and it led them to hot waters, eventually costing their reputation. Five years passed and an untoward reunion takes them back to their previous ordeals while inadvertently helping each other out.