Goku is a teenager in high school where he doesn’t fit in and he’s not very bright. He has a crush on the rich girl Chi-Chi and is friends with no one. When Chi-Chi discovers Goku knows how to use Ki (energy that forms into concentrated bursts such as the Kame Hame Ha) too, she invites him to a party she’s throwing at her mansion. The party just so happens to be the night of Goku’s birthday, and Goku decides not to stay at home with his adopted Grand father (Gohan) who prepared a special meal for him. At the party, Goku is confronted with bullies who he dispatches of easily. Chi-Chi, impressed, shows affection for Goku. However, Goku senses his Grandfather is in danger at home and runs back to his house. There he discovers it’s been destroyed. Lord Piccolo has returned.

Grandpa Gohan, dying from injuries inflicted by Lord Piccolo, makes a request to his adopted son Goku, to find Master Roshi and gather the seven Dragon Balls, which when gathered can grant any wish, before the evil Lord Piccolo does. On Goku’s journey to fulfill his Grandfather’s request, he meets Bulma, who has a useful Dragon Ball locator. They travel together after a confrontation and find Master Roshi living in the center of the city. Roshi thinks Goku is a thief and fights him, but after the fight he realizes that Goku is Gohan’s son. Roshi joins Goku and Bulma and together they look for the remaining Dragon Balls. When their journey takes them to the desert, they fall into a trap set by the bandit Yamcha. Yamcha spies on the gang and overhears Roshi’s explanation on Piccolo and the Dragon Balls. Yamcha then agrees to help them find the Dragon Balls and save the world from Piccolo. After their quest, Piccolo’s sidekick Mai steals all the Dragon Balls Goku and team acquired and Goku and his friends must rush to the Dragon Temple where Piccolo is attempting to resurrect the wish-granting Dragon Shen Long with the 7 Dragon Balls (so he can wish for immortality) and stop him from making a wish. They miraculously ruin Piccolo’s attempt at resurrecting Shen Long and then engage Piccolo. Yamcha kills Mai, who had a gun on Bulma. Piccolo reveals that Goku is an alien sent to earth to destroy it, but forgot his mission when he hit his head as a baby. Piccolo then transforms Goku into his inner Oozaru (beast-like alien monster), but Goku eventually snaps out of the form and then uses his iconic beam attack “Kame Hame Ha” and defeats Piccolo. During the fight, Master Roshi tragically died but Goku and gang use the Dragon Balls to summon Shen Long and wish him back to life. With the world at peace, Goku enters a dojo where he joins Chi-Chi in a sparring match.

At the end of the movie there is a cliffhanger where Piccolo is laying in bed with a mysterious woman nursing him back to health.