Track and Field star Ki Seon-gyeom has dedicated his entire life to being the best in his sport, but his strong work ethic has left him lonely and without many meaningful relationships. In a chance encounter, fate brings Seon-gyeom to meet Oh Mi-joo, a hard-working young woman who dreams of becoming a successful film translator. The two end up working together, but soon find their feelings for one another too strong to contain and love blossoms between them. "Run On" has the same light, romantic tone as "Twenty-Five Twenty-One," with a unique storyline that makes for an incredible watch.