Kami was the guardian of Earth for a long time, but Dende is currently
Sent to planet Earth when his homeworld Namek was about to be
hit by a comet, Kami-sama
created the Dragonballs on the new world. He wanted to be pure good
and so he purged his evil and
'impure' side. Unfortunately, his evil thoughts formed into Piccolo-Daimao.
They have a spiritual link,
so if one of the two dies, both of them die. As the guardian of Earth
and creator of the Dragonballs
on Earth, Kami plays a key role in the story.