Yeah yeah, Folder 5 is the band, Believe - the song. It was used as the second opening song in the anime One Piece. End of facts, now for the laughs :) The choreography is quite funny (as in most japanese videos), but I espiecially loved the close-ups in the end, with the huge disco ball in the background. And I really believe none of the girls has straight teeth :P Becoming quite a hobby of mine - searching for those lame and/or funny japanese (and other - that guy from Kazachstan! :D ) videos. Have fun watching.