在这部龙珠GT特别篇：悟空外传! 勇气的证明四星珠!动画片中,妄图灭亡赛亚民族的贝比，在最终决战中败于孙悟空的手下，历经千辛万苦地球迎来了难得的和平，此后便是长达一百年的快乐时光。曾经在人们心中留下无数珍贵回忆的Z战士和GT战士相继作古，而今只有小芳以婆婆的身份训练与悟空同名且相貌如出一辙的赛亚人后代。只不过，这个小悟空似乎缺乏祖先那样的勇气，无论武功还是意志方面都令小芳颇为头疼。某天，小芳婆婆突然病倒，难过的小悟空想起了神龙的传说。为了拯救最爱的婆婆，小悟空决定搜集龙珠，实现愿望。 这个稚嫩的孩子鼓起勇气踏上了多舛的旅程……©豆瓣
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.
