City Hunter: I remember the spoiled brat Kim Na Na was a bodyguard for dragged her to a nightclub. And there she bumps into Lee Min Ho ;^)
Hana Yori Dango (and therefore probably Boys Over Flowers, though I can't remember clearly): Tsukushi goes to a nightclub and gets framed in order to make Domyoji jealous :^/
I Need Romance 3: the male lead is a musician and sometimes a DJ in nightclubs. I remember there being a few scenes of that, and I'm pretty sure there was at least one scene involving the two leads (she tried flirting him because he was very cool as a popular DJ, but he rejected her and purposely made her jealous with another girl, because he truly has a crush on her though she doesn't know it, and blablabla)
Que Sera Sera: at the beginning there are many scenes at clubs, but not necessarily between the male lead and the female lead (it's really because he's a gigolo of sorts, and that's his hunting area). Later on the female lead briefly works at a kind of club.
Good luck :^)
