Dragon Ball Z

Goku was merely a baby when Grandpa Gohan found him near his forest home. Trained by the martial arts master since he was very young, Goku soon can control a well spring of power. In fact, anyone who's met him would say he is "out of this world," and they wouldn't know just how right they were. He was originally sent to destroy the Earth by the Saiyans, a race from a planet on the other side of the galaxy. Luckily for us, he hit his head, and his memory was deleted. When Bulma stumbled into him on her quest for the dragon balls, she decided to take him along with her, after all, he did have the four star dragon ball. During their journey they meet Oolong, Puar, Yamcha, Chichi, Turtle, Master Roshi, and the Ox King.

Years later, Goku ends up marrying Chichi and they have a son, Gohan. One day, Goku's past comes into play when a Saiyan warrior decides to come to Earth to check on his younger brother, and find out just how horribly he failed his mission. Determined that Goku would join him and the other Saiyans in conquering worlds for Freiza, he kidnaps Gohan and tells Goku that he must kill 100 people to get him back. The kind-hearted Goku refused to do no such thing, but his adamant about getting his only son back. Fed up with Gohan, the Saiyan Warrior throws him into the pod that he arrived on Earth in, and waits for Goku to finish his task. His scouter pick up a high level of energy, but he thinks it's broken, because when he turns around to see where it's coming from, it's just the kid he kidnaped. Little did he know just how right the scouter was.