It's been a long time since your last relationship... 3 years ago, you were dating a wonderful guy named Jaeyun, with whom you had a strong love. But you broke up on the eve of how you found out about your pregnancy. You told him about it, but he didn't take your words seriously, thinking that this was how you wanted to keep him. He chose a career instead of being a father.

3 years passed. You had a little son, whom you named Kai. He looked a lot like Jaeyun. Jaeyun himself became the CEO of a large company, whose sales were key to the Korean economy.

On Christmas Eve, you were in the center of Seoul and walking with Kai. The boy was running and jumping, enjoying life. When suddenly you noticed Jaeyun walking towards you in the company of some girl. It was a fiasco...