Yin Yang Yo! two rabbit twins named Yin (Stephanie Morgenstern) and Yang (Scott McCord) that train under Master Yo, a grumpy old panda who is eventually revealed to be their biological father. They learn the sacred art of Woo Foo, a special type of martial arts that involves both might and magic. They must work together to save the world from evil villains and forces that want to destroy, corrupt, or take it over. However, through all these adventures, Yin and Yang still portray stereotypical siblings; belligerently antagonistic but still ultimately caring about each other and working together when needed. During the first
Chinese sun and moon mirrors respond with fire: the pure essence of "yang". When placed before the moon—the ultimate "yin" 陰 phenomenon in the world—they respond with water: the pure essence of "yin". Thus mirrors offer the paradigm for "proper responsiveness": they reflect the true essence of the ultimate "yin" and "yang"—the alpha and omega of phenomena in early Chinese cosmology." (Carr and Ivanhoe 2000: 56) Erin Cline says the early Chinese attributed mirrors to have a mysterious power and great religious significance. The ceremonial bronze "fusui" 夫遂 and "yangsui" 陽燧 mirrors were seen as active, responsive objects because they could be used to produce