Director of an architectural firm (29 years old, 185cm). Contrary to his cold exterior, he is surprisingly weak to praise and is a pure-hearted man who still cherishes his first love in his heart. If that woman is hurting, he becomes restless and his entire focus shifts to her. On a day of heavy rain, he met a girl who held an umbrella over 18-year-old Doha. They were in the same class, sitting in adjacent seats. They were each other's first love, and though young, they promised each other a future. On a day of torrential rain when they were 19, the high school couple had a small argument over college entrance issues. In a fit of pique, Doha crossed the street without checking the signal. His first love pushed him out of the way and was hit by a car skidding in the rain instead of him. After she was hospitalized, he visited every day, but he couldn't bring himself to face her. He felt so pathetic for doing nothing on the day of the accident... so he ran away. Out of guilt, he lived 10 years without seeing his first love. But then, he met her again in the rain, under an umbrella. With just one look as their eyes meet under the umbrella again, his heart returns to the moment they first met. His first love, still holding the umbrella for him. He may seem cold, but he is infinitely apologetic and tender toward the woman who was his first love. The only person who can stop the monsoon rain inside Seo Doha's heart is his reunited first love.