certified Triple Platinum by the  RIAJ . The leader of the group is  Kim Taeyeon . The other members are  Jessica Jung ,  Sunny ,  Tiffany ,  Kim Hyoyeon ,  Kwon Yuri , Choi Sooyoung ,  Im Yoona  and  Seohyun . Watch HAPPY TOGETHER With TAEYEON TIFFANY JESSICA English Subs After clicking