Plot: Dragon Ball Z picks up five years after the end of the Dragon Ball anime, with Goku now a young adult and father to his son, Gohan. A humanoid alien named Raditz arrives on Earth in a spacecraft and tracks down Goku, revealing to him that he is his long-lost older brother and that they are members of a near-extinct extraterrestrial warrior race called the Saiyans (Saiya-jin). The Saiyans had sent Goku (originally named "Kakarot") to Earth as an infant to conquer the planet for them, but he suffered a traumatic brain injury soon after his arrival and lost all memory of his mission, as well as his bloodthirsty Saiyan nature. Goku refuses to help Raditz continue the mission, which results in Raditz kidnapping Gohan. Goku decides to team up with his former enemy Piccolo in order to defeat Raditz and save his son, while sacrificing his own life in the process.