Complex sentence: She then starred in the omnibus film "Romantic Heaven" but her big break did not come until 2010 when she was selected to star in a lead role in Song Ji-na's drama "What's Up" which aired in 2011.
Split into simpler sentences: She then starred in the omnibus film "Romantic Heaven". In 2010, Kim was cast in her first leading role in Song Ji-na's drama "What's Up" which aired in 2011.