Dragon Ball GT: A Hero's Legacy (1997)

Goku Jr. is the great-great-grandson of the legendary warrior Goku, but unlike his predecessor he's not a brave fighter. He's constantly picked on by school bullies--his grandmother Pan sees this and is worried, but even though Goku Jr. is not a strong and powerful saiyan, he has a kind heart, and Pan loves him. When Pan gets sick, Goku Jr. realizes that he must do something if he doesn't want to lose her. Then he remembers about the legends of the Dragon Balls. It was told that they grant a wish to the bearer, and Goku Jr. needs a magical wish more than ever, so he sets out to find the dragon ball that his grandmother told him about.