Now the younfest-ever J-pop group has emerged, with seven kids in their teens, ranging from 11-13. They are known as Folder, or Kou Dai Xiao Hai (Pocket Kids), on the idea that they are so small they can fit inside a folder or a pocket. The seven singers take on R&B and even don Afro wigs in a remake of I Want You Back, a 1970s hit by Jackson 5.