The Z Warriors discover an unopenable music box and are told to open it with the Dragon Balls. The contents turn out to be a warrior named Tapion who had sealed himself inside along with a monster called Hildegarn. Goku must now perfect a new technique to defeat the evil monster.

Five years have passed since the fight with Piccolo Jr. and Goku now has a son, Gohan. The peace is interrupted when an alien named Raditz arrives on Earth in a spacecraft and tracks down Goku, revealing to him that that they are members of a near-extinct warrior race called the Saiyans.

Long ago in the mountains, a fighting master known as Gohan discovered a strange boy whom he named Goku. Gohan raised him and trained Goku in martial arts until he died. The young and very strong boy was on his own, but easily managed. Then one day, Goku met a teenage girl named Bulma, whose search for the mystical Dragon Balls brought her to Goku's home. Together, they set off to find all seven and to grant her wish.