The series follows the adventures of Penn Zero, who unexpectedly inherits the job of his parents: being a Part-Time Hero. Penn must zap into various dimensions to take on the role of the hero in that world and save the day in their place.

The show is about two rabbit twins named Yin and Yang 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.