Answer
Boys Over Flowers, a popular 2009 South Korean drama, featured Koo Hye-sun as the lead actress. The drama follows the story of Geum Jan-di, a bright and optimistic girl from a poor family, who attends an elite high school for the wealthy. There, she encounters the F4, a group of four handsome and arrogant boys led by Gu Jun-pyo, played by Lee Min-ho.