The 13-year-old girl who dances the whistle in Japan is called Kyoka Yamamoto Kyoka
Here is some information about her
Yamamoto Kyoka Kyoka (Tall)
Birthday:1996.4.24
Height:Currently 165cm
Winner of the 2007 National KIDS DANCE BATTLE in Japan
Winner of the 2008 National KIDS DANCE BATTLE, the largest of its kind in Japan
This is the first time that she has been on the show in the United States. Street Dance Competition Champion
2008 Champion of SPROUT, Japan's largest national KIDS DANCE BATTLE
PS: She is in a group with Ikeda Maikaze Maika named RUSHBALL
Their official website /v_show/id_XNzg1MjMxMTY=.html Participation in the Starking, a Korean program where they danced with the Oriental God Ki.