Gee ". 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 Music Core - Seohyun Tiffany Taeyeon MC cuts English Subs After clicking our links please wait