Thirty-year-old Yun-woo bumps into a high school student in the elevator while on his way to work. His heart starts pounding at this teenager's boldness. At a subway station, KANG Sook can't stop staring at the long-haired, beautiful Ha-kyung. Ha-kyung breaks up with KANG Sook only a few hours after they first meet. However, KANG Sook has already fallen in love with her.
- Alternative title : "Pure Love", "Crush on You", Korean: Sunjeong Manhwa
Kwon Yeon-woo (Yu Ji-tae) is a somewhat naive 30 year old low-level civil servant who works in a city hall branch office. Although he is thirty, he is still innocent for his age and has been on numerous unfruitful blind dates in search of a suitable wife. After moving into a new apartment, he encounters a high school girl, Soo-young (Lee Yeon-hee), and sees her on his way to work every morning. She is a cheerful and eccentric 18 year-old who lives with her mother downstairs from him. When one day she forgets the necktie of her school uniform at home she asks Yun-woo to lend her his. From that day on the two meet more frequently and a deeper friendship evolves and over time, the two begin to develop feelings for one another.
Meanwhile, 22 year old Kang Sook (Kang In) ,who has just started working at the branch office, approaches the 7 years older Kwon Ha-kyeong (Chae Jeong-an) at a subway station and falls head over heels in love with her , a melancholy woman who wanders around taking pictures. She is still holding onto an old flame, and keeps looking for traces of that lost love every day. But even though the two have some dates, Ha-kyeong rejects her new boyfriend, eventually, because the scars of her prior relationship are just still too deep for her to start a new one. Kang Sook continues to woo her, regardless of her living in the past. Yun-woo on the other hand must realize that society presently does not approve the kind of relationship he has with the schoolgirl Soo-young.
Can their futures lead to a happy ending?