The story in Dragon Ball is based on several main characters, including Bulma, Chiaotzu, Chichi, Krillin, Piccolo, Goku and Yamcha.

Pilaf

The purpose of Pilaf is to borrow the power of Dragonball and to conquer the world.
Pilaf has two subordinates.
They try to deprive of Dragonball that Bulma has.

Mai

She is one of the subordinates of Pilaf.

Shu

He is one of the subordinates of Pilaf.

Tao

Tao is well-trained mercenaries.
To knock down Goku, he was employed.
Uses a dirty trick in order to win

Launch

Launch has two characters.
One is very strong and belligerent, Other is obedient.
It changes when sneezing.

Master Roshi

He is an expert of military arts, and　hard master of Goku.

He has grown old for hundreds of years.

Upa

He is son of sentry of Karin tower.
His father was killed by Tao.
He was very sad.
Goku that collected Dragonball revived his father.