Socrates said that a kiss is the greatest thief that steals one's heart. However, for Heung Mi it's different. She hears the sound of an ambulance instead of a heavenly bell whenever she kisses someone due to anaphylactic reactions. Meanwhile, Wan Jun has a genetic disease that can only be treated through this most peculiar woman. The two of them agree on dating under certain conditions for the sake of treating each other's illnesses. Watch their romantic adventure unfold!