Hello :D
I'm looking for dramas where the main guy - just some ordinary guy - falls in love with the female lead (she may fall for him too, but I don't mind if she doesn't), and then they got separated. Years pass and the main guy meets the girl again (and very important - he recognizes her!), but this time he's rich and successful (he might be an actor, CO, whatever). He fights for her, of course, and is pretty jealous of every guy, because he was the first who felt for the girl ;)
Fox examples: My Love Eun Dong, Cunning Single Lady, Discovery of Romance.
Similar dramas: EXO Next Door (I guess, but he doesn't recognize her...), City Hunter (well, he does know her and love her even before they meet :P).