Ten years have passed since Goku left his friends and family to hone his skills. But Goku soon finds himself helpless against the mystical power of the Dragon Balls and an accidental wish made by the devious Emperor Pilaf. His desire; that Goku once again become a child! Not daunted by this small setback, Goku, together with Trunks, and his own granddaughter Pan, blast off into the outer reaches of space in search of the mysterious Blackstar Dragon Balls. But these Dragon Balls have a fatal secret: if not collected within one year Earth will be destroyed.
100 years after the end of DBGT, all the heroes of Earth have died...except for Pan, the granddaughter of Son Goku. Pan has a grandchild named Goku Jr. However, he does not have the bravery of his great-great-grandfather. Pan suffurs a heart attack, and Goku Jr. believes that he might be able to save her with the power of the 4 star Dragon Ball. Along with the school bully, he tries to find the ball...and unleashes his hidden bravery and power.
Years after the end of the Dragonball GT, the story continues in this special with Son Goku's now eldery granddaughter Pan, and a new generation of super saiyajins, the great-great-grandsons of Goku and Vegeta
Goku and Trunks are on the verge of defeat, finding themselves in the sinister grip of a mad scientist who wishes to use their Saiyan bodies in his twisted experiments! But what's this? Goku is a child?! The grandest adventure of all begins now!