The dance “Yokihi” is based on the Chinese historical figure Princess Yang Kwei-Fei, who was the beloved concubine of the Tang Dynasty emperor Hsuan Tsung (Genso in Japanese). For more information on this story, see http://www.taleofgenji.org/yang_kwei-fei.html
For the last part of the dance, see http://www.youtube.com/watch?v=V_mgamVag68
