Claim: Girls' Generation includes Sunny.

Girls ' Generation , also known as SNSD , is a South Korean girl group formed by S.M. Entertainment . The group is composed of eight members : Taeyeon , Sunny , Tiffany , Hyoyeon , Yuri , Sooyoung , Yoona , and Seohyun . Originally a nine-piece group -LRB- with Jessica , who later departed from the group in September 2014 -RRB- , Girls ' Generation debuted in 2007 with their Korean eponymous debut album . Though the album gained some attention , it was not until 2009 that the group rose to fame with the single `` Gee '' , which claimed the top spot on KBS 's Music Bank for a record-breaking nine consecutive weeks and was named the most popular song of the 2000s in South Korea by Melon . Girls ' Generation further consolidated their popularity on the South Korean music scene with follow-up singles `` Tell Me Your Wish -LRB- Genie -RRB- '' , `` Oh ! '' , and `` Run Devil Run '' , which were released in mid-2009 and early 2010 .   In mid-2010 , Girls ' Generation signed with Nayutawave Records -LRB- present-day EMI Records Japan -RRB- to venture into the Japanese music scene . Their June 2011 self-titled Japanese debut album peaked atop the Japanese Oricon Albums Chart and became the first album by a non-Japanese girl group to be certified million by the Recording Industry Association of Japan . The group 's third Korean studio album The Boys was released in October 2011 and became the best-selling album of 2011 in South Korea with sales of over 380,000 copies . An English version of the single `` The Boys '' was released by Interscope Records in an attempt to expand the group 's endeavor to the global music scene . The group 's 2013 fourth Korean studio album I Got a Boy was supported by the single `` I Got a Boy '' , which was subjected to major attention from Western media following its winning the Video of the Year award at the inaugural YouTube Music Awards . Their fifth Korean studio album , Lion Heart , was released in 2015 .   Girls ' Generation 's signature musical styles are characterized as electropop and bubblegum pop , though their sounds have varied widely , incorporating various genres including hip hop , R&B , and EDM . They have sold over 4.4 million albums and 30 million digital singles as of 2012 . The group 's immense popularity in their native country South Korea has earned them numerous accolades and the titles `` The Nation 's Singers '' and `` The Nation 's Girl Group '' . Girls ' Generation is also deemed one of the prominent figures of the Korean Wave and one of the most popular K-pop acts internationally . They are the first Asian girl group to achieve five music videos with over 100 million views on YouTube : `` Gee '' , `` I Got a Boy '' , `` The Boys '' , `` Mr. Taxi '' , and `` Oh ! '' . In Japan , they became the first non-Japanese girl group to have three number-one albums on the Japanese Oricon Albums Chart , and their three Japanese concert tours attracted a record-breaking 550,000 spectators , more than any other Korean girl groups .