Prologue to Battle! The Return of Goku!

Long ago, Bardock, a Saiyan warrior died in an attempt to stop Freeza, a galactic tyrant who ruled over the vast reaches of space. But before Freeza destroys Bardock's home planet, one space pod seems to have escaped only moments beforehand. Kakarrot, Bardock's son, had escaped the planet's explosion and was sent to Earth to follow through with Freeza's orders of conquering it. Upon crash landing on Earth, however, Kakarrot is found by an elderly man, Son Gohan, who raises him as his own, naming him Son Goku. Years pass and Goku ends up serving as Earth's greatest protector, completely unaware of his Saiyan heritage. But it seems that Goku is not the only survivor of his home planet, as another Saiyan has reached Earth to remind him of his true purpose.