Smile, You (2009)

Seo Jung In is the kind-hearted, but spoiled daughter of a wealthy family. When the family's financial bubble bursts, her fiancée dumps her at the altar and her family is forced to rely on the kindness of their former chauffeur's family. While adjusting to life in their crowded, two-family home, Jung In and the Kangs' son, Hyun Su, begin to clash. Will these two find a way to get along, or will their initial irritation with one another blossom into something more?