a multi-couple family drama where we get to see generation gaps and different personalities learning to live with each other

Haven't watched Runaway Sweetheart yet, but story-line seems similar to the plot in You're Beautiful. A girl who replaces her brother in a idol boy-band, where the other members end up questioning their sexuality. You're beautiful is probably a lot better and more cuter!

Both stories about a young girl getting married, except in this one, the girl is supposed to marry the main lead's brother. The drama that made me fall for Yoon Kye-Sang. It's old but still one of my favorites.