Chaeyeon and Sungmin made a mistake five years ago. Chaeyeon doesn't regret it, but she sometimes wonders if Sungmin does. He's hardly ever there when he should be and when their son needs him, the job that took him away always interferes. She's tired of being lonely, tired of being a single mother, even if she loves her son. Can she ever move past what happened with Sungmin to find the one who'll love her for real this time?