Being the eldest child in her family and left alone with a brother, Kim Jun, to be raised by herself is her destiny. Nevertheless, she loved her brother more than anything in the world that she sometimes thought her brother has slowly became her son. Ever since her parents passed away, Sunny struggled for their lives. It was a kind of traumatic event for her to begin with. Young and alone, something that other kids wouldn't ever imagine. The siblings were nothing more than balls being passed from one relative to another. The situation forced her to be independent, to find a place to live soon as she finished her education.

Knew that having such a huge childhood trauma, she decided to major in psychology. She though, excellently completed her education until she became a psychologist. Thanks to her grandparents who secretly funded her after their first meeting when she was in high school, long story. As a psychologist, she wanted to help those people in need, specifically those people who are battling against their selves with mental or emotional illness. Beside the generous funding, she was also a hard worker so she managed to franchised a fast food restaurant for more income.

Being successful and all she knew her life wouldn't be complete without a lifetime companion. After a long search, she finally found the man of her life. She was really in love, the proposal was really sweet, everything was really perfect until she found out that the man was still officially married to someone and he has been blessed with two daughters. She was deceived, everything fell apart on the dress-fitting day which was really important to her. Since then, Sunny promised to herself not to open her heart easily anymore. She always knew that no one except her brother can be trusted. Not even the one she loved dearly. Years after years she managed to move on. She built one or two relationships with another but none of them work. One thing she was sure about her life, she wasn't made to be weak. She was made to live with a series of unfortunate events, traumas and fear but still got to act like everything was fine. Love was never on her side from the start, never.