Go Ho's Starry Night , a short drama fits perfectly what you are looking for. I really enjoyed it!
http://mydramalist.com/16921-go-hos-starry-nightI Will Teach You Love, Great, but it's a movie, not a drama.
The following have a similar theme but fit more losely, or the couple get together sooner than lately, or there are another themes that are more relevant to the story, etc.
Boss and Me (CH)
Healer (The hero has a secret identity and his average alter ego is rejected by the girl who is atracted to the mistery man)
Protect the Boss
The Best Love
Another Oh Hae Young
Heartstrings
18 vs 29
A Gentleman's Dignity (Secondary couple)