Question: Jang Yeong-sil is a historical drama television series starring a South Korean actor best known for his role in what 2006 hit drama series? 
Sentence (from "Happy Together (1999 TV series)"): Starring young actors who would go on to become Korean TV and film stars, the hit drama revolves around five children who were separated at the death of their parents, and the love, conflicts, and reconciliation that these siblings go through when they meet again as adults.
Relevant evidence: No