This show is about two anthromorphic rabbit twins named Yin and Yang that train under Master Yo, a grumpy old panda. They learn the sacred art of Woo Foo, a special type of martial arts that involves 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. They gain allies as well as enemies along the way. Among the villains they face are the demonic Night Master, crazy Ultimoose, psychotic pro-female rights activist Saranoia, Carl, the evil cockroach wizard, as well as Yuck, the evil green rabbit with a terrible hygiene.
But through it all, Yin and Yang portray typical siblings; almost always disagreeing with each other but working together to fight evil.