Girl's Day
In March 2011, they released the third digital single album, Girl's Day Party 3. "Twinkle Twinkle" (), which is the title song of this album, made Girl's Day popular. Girl's Day won the first prize of the charts for the first time. Also, the dance of this song which is called "Mam Mam Ma dance" became famous. In September 2011, they released Girl's Day party 4 for their fans. In October 2012, Jihea announced that she was leaving the group. Then they released Girl's Day Party 5. The title song of this album is "Don't forget me", which people liked.