Girl's Day (걸스데이) is a South Korean all-girl quartet signed with DreamTea Entertainment. Initially gaining public interest performing dance flash mobs in the streets of Seoul, they debuted in July 2010 with the release of their first song, “Tilt My Head” (갸우뚱), an electro-pop song. The current lineup is made up of members So Jin (소진), Min Ah (민아), Yura (유라), and Hyeri (혜리). In September 2010, it was announced that two members of the original lineup, Ji Sun and Ji In, would be leaving to pursue other activities. They would soon be replaced by two new members, Yura and Hyeri. The new lineup was showcased with the release of their second lead single, “Nothing Lasts Forever” (잘해줘봐야), marking a depature from the autotune-heavy “cute” pop they debuted with and showing off a mature dance-pop sound. In December of that year, Girl’s Day starred in their first television show alongside South Korean boy band U-KISS. The show, “We Are Dating”, was a spinoff of the Korean hit, “We Got Married”, and paired three members of each group in the first season. In early 2011, they collaborated with Japanese artist Nami Tamaki (玉置成実) on her song “Girlie Night”. In March 2011, they released their third lead single, “Twinkle Twinkle” (반짝반짝), thrusting them further into popularity. They released their third mini album "Everyday 2" on April 17, 2012, and a single album "Girl's Day Party #5" was released in late October, 2012. On October 17, 2012, it was announced that Jihae had left the group due to personal reasons. Sites: En.Wikipedia & Ko.Wikipedia