These days I'm die hard fan for these kind of drama  you know ... like in time with you or replay 1997 or what's up fox they were childhood friend .... or like emergency couple they were ex-husband and ex-wife  .. or like pinocchio they were fake uncle and nephew or and they grew up together under the same roof :) ... or replay 1994 they were just like a real brother and sister 
It would be GREAT if the one who falls in love first is the guy
Thank you very much :)
9 Ends 2 Outs
I Need Romance 3
18 vs. 29

These are close to what you're looking for. In 9 Ends 2 Outs the main leads are best friends. In I Need Romance 3 the leads grew up together, although later are estranged. In 18 vs. 29 the leads are married, but the wife gets amnesia; it shows how they met, in high school, and their memories of each other during the end of each episode.