The Stigma of Sponsorship

What went wrong? Was it the moment she dared to fall in love with Gu Je-heon, the only son of her benefactor? Or was it when she gave up her life as a pianist and gave birth to his child alone?
Yeon-jae abandoned everything and ran away to raise the child of her first love on her own. But five years later, her first love suddenly reappears before her…