The TV movie is a prequel to the original Dragonball series, focusing on Son Goku's father Bardock and his desperate struggle to save his planet, Vegeta, from destruction by Freeza. The story also reveals how Kakarotto, Son Goku, ultimately ends up on Earth.

Dragon Ball Z: Bardock - The Father of Goku
Bardock, Goku's father, leads a courageous uprising against the powerful Frieza, driven by a desire to protect his family and defeat the tyrannical force that threatens their existence.