Song Ji-eun, better known mononymously as Jieun, is a South Korean singer and actress best known as a member of the South Korean girl group Secret. Aside from her group's activities, she has released several solo songs and participated in various OSTs. In 2011, her second single, "Going Crazy" featuring Bang Yong-guk, went to become her first number one single on the Gaon Chart as a solo artist.