The peaceful life of Son Goku is shattered when a powerful alien warrior named Raditz arrives on Earth, revealing that Goku is actually a member of a fierce extraterrestrial warrior race called the Saiyans. Raditz claims to be Goku's long-lost older brother and demands that Goku join him in conquering distant worlds. When Goku refuses, Raditz kidnaps his young son, Gohan, to force his compliance. Left with no choice, Goku forms an unprecedented and uneasy alliance with his former archenemy, Piccolo. Together, the two legendary martial artists track down Raditz and engage in a desperate, earth-shaking battle to rescue Gohan. Piccolo unleashes his secret weapon, but the victory requires an ultimate, heart-wrenching sacrifice from Goku that changes the fate of the world forever.