Seung Min is a 35-year-old successful architect. One day, when he was working in his office, a woman hired him to redesign her old house on the Jeju island. Seung Min realized she was Su Yun - his first love 15 years ago when both were students in class 101 Architects in college. When designing the house, suffering and anxiety memories in the past rushed back, which made they remember their tragic first love.