Dragon Ball Z: Saiyan Saga

After years of peace since the defeat of Piccolo Daimaoh, Goku now lives peacefully with his wife, Chi-Chi, and their son, Gohan. But everything changes when a mysterious warrior called Raditz arrives on Earth, revealing that he is Goku's brother and that they both belong to the warrior race of the Saiyans, a brutal people who conquer planets.