Sonyeo Sidae  ) is a nine-member  South Korean   girl group  formed by  SM Entertainment  in 2007. The nine members are:  Taeyeon ,  Jessica ,  Tiffany ,  Sunny ,  Yuri ,  Hyoyeon ,  Seohyun , Sooyoung  and  Yoona  . They are often referred to as  SoShi  ( 소시 ), or  SNSD