Till Death Do Us Apart

"Let's run away together, Joohyun ah.. A family with just the two of us.." "But.. It's impossible.. You are to be married! I don't want the whole nation to blame me because of this!" When two Best Friend falls in love and one happens to be the daughter of a mistress while the other is the eldest son of the President and the upcoming heir of Palette Entertainment. Everything they do were bound to be wrong and invite trouble all around but will their love be strong enough to overcome all the problems that are coming? Or the promise they once made will just be a part of their memories?