This little girl is playing a tradidtional New Year’s game called hanetsuki in Hamarikyu Koen Park. The game is like badminton, but is played without a net. The idea is just to keep the shuttlecock in the air. The game used to be extremely popular at New Years, and if your opponent let the shuttlecock fall, you were allowed to put a black ink mark on the person’s face.
For more information about hanetsuki, visit: http://www.englishjapaneseonlinedictionary.com/Japanese%20textbook/pages/Japanese_textbook_76.htm or http://www.japan-guide.com/e/e2261.html