Son Goku is the greatest hero on Earth. Five years after defeating the demon king Piccolo, he`s grown up and had a family--he`s married, and he has a child, Son Gohan. But what is the real reason for Goku`s incredible strength? A visitor from outer space arrives bearing terrible news--Goku is an alien, and the visitor, Raditz, is Goku`s brother! When Raditz turns out to be a ruthless killer, Goku must fight his incredibly strong brother to save his family and the entire human race. A surprising alliance may be Earth`s last hope: Goku will team up with his old enemy Piccolo...archenemies united to save the world!