Bina's dad passed when she was young and her mother constantly worked. It was only when she started babysitting Heeseo and Heewon that her loneliness faded and being happy seemed like a less far off dream. Cut to the present day and Bina is now a successful, albeit very busy, surgeon. She's finally grown into a self-reliant adult, but Heewon's feelings towards Bina have also seemed to mature.