Run On tells the love story of Ki Seon-gyeom (Im Si-wan), a former sprinter who is working to become a sports agent, and Oh Mi-joo (Shin Se-kyung), a subtitle translator.
Innocent but caring, Seon-gyeom was a national Track and Field athlete who always got second place. Seon-gyeom's parents were both very busy and his only sibling was not a companion. As a result, he grew up largely without social interaction. Oh Mi-joo is his first real friend. Despite his lonely existence, he grew up in a privileged environment. He considers the world as friendly.
Oh Mi-joo works as a film translator who loves movies and thinks that every movie has a deep message if you watch it thoroughly. She grew up an orphan. As a result, she had to work very hard in order to get where she is now. She considers the world exceptionally harsh.
CEO of Dann Agency. She is a very busy woman and very passionate about what she's doing. Grew up in a family that lacks love, she doesn't know how to express her feelings in the right way so she is known to be rude, sarcastic, and very straight-forward for a while until she learns what it means to have friends and true love. She had to give up the love of soccer because of her family's tight rules. She also has a unique taste in arts, paintings especially.
Cheerful and childlike, Yeong-hwa is the only person who could crack open Dan-ah's cold heart. He is a college art student who donates his paintings to a nearby cafe. He has his own way of channeling his feelings into his paintings.
A very successful actress who is known as "The Queen of Cannes".
Ryu Sun-young as Ki Eun-bi
South Korea's number one golfer and Ki Seon-gyeom's older sister. She loves her brother dearly and always had his back whenever he had a fight with their father.
Seo Dan-ah's Family
Lee Hwang-eui as Seo Myung-pil, Dan-ah's father and chairman of the Seomyung Group.
Lee Shin-ki as Seo Myung-min, Dan-ah's half-brother. He is younger than her but their father registered Dan-ah's birthday after he was born.
Choi Jae-hyun as Seo Tae-woong, Dan-ah's youngest half-brother. He is in the fictional K-pop group AtoZ. It is implied he wasn't born in Korea and had to learn Korean.
In the table above, the blue numbers represent the lowest ratings and the red numbers represent the highest ratings.
This drama airs on a cable channel/pay TV which normally has a relatively smaller audience compared to free-to-air TV/public broadcasters (KBS, SBS, MBC and EBS).
^Yoo, Byung-cheol (2021-02-04). "'런 온' 김시은 종영 소감"행운 같은 작품"" ['Run On' Kim Si-eun's impressions of the end of the show "A work like luck"]. Korea Economy TV. Archived from the original on 2023-05-29. Retrieved 2023-05-29.
^Kwak Hyun-soo (January 20, 2021). "김선호, JTBC '런 온' 특별 출연 확정 [공식]". sports.donga (in Korean). Archived from the original on March 5, 2021. Retrieved January 20, 2021.
