Movie number 12 starts off with Pikkon and Goku fighting in a tournament in other world and it appears as though neither are losing and in the background you can see the North, South, West, and East Kaios along with the Grand Kaio. Then it shows a machine which is used to cleanse impure souls and it starts to malfunction and the guy who is down there gets sucked into it and while this is going on Goku and Pikkon are alerted of this. After the machine malfunctions a monster named Janamba comes out and he puts a covering around king Yemma's place and makes jelly bean like orbs all over the place.

Goku and Pikkon arrive at Yemma's place and Yemma tells them the monsters name and that he's on top of the building and Goku and Pikkon go up to view him and discover he is a big huge white creature who acts very childish and likes to repeat its name. Goku then tells Pikkon to try to break through to King Yemma while he fights off Janamba. Goku then leads Janemba to hell and they proceed to fight.

Janemba at first is a problem for Goku because even though he acts like a child he is a very strong fighter but after a little while of them fighting Goku goes level 3 and punches deep into Janemba's belly and Janemba changes into his next form. While this was going on back on earth Gohan, Videl, Trunks, Goten, and some others called upon Shenron to send the dead back to where they belong but Shenron said that it is not within his powers and with that said Videl and Gohan dawned there costumes and went around killing the dead while Trunks and Goten did the same. As Gohan was flying around Frieza came back and saw Gohan and said that he was the son of Goku and Gohan flew up to him and punched right through him with one punch. Also Hitler and his army came back and were terrorizing the city, Trunks and Goten fought with them and eventually fused into Gotenks and used kamikaze ghost attack on Hitler and his army.

After Janemba transformed into his second form Goku attacked him in level 3 but was no match for the strength of Janemba's second form. At the same time this was happening Pikkon was trying to break through to King Yemma but was not succeeding. Janemba kept on landing blow after blow on Goku and then Janemba created a sword out of nowhere with an odd ability, when he swung the sword the slash would cut through anything and keeps on going for a long time. Goku got cut in the arm by one of the swings from this sword and hid in some jelly like substance but Janemba sliced it up and Goku quickly retreated.

Then Vegeta came and started attacking Janemba but he to be no match for his awesome power and then Goku and Vegeta hid in a spot which was surrounded with balls with spikes all over them. Goku tried to convince him that fusion was the only way they would beat him and after some time Vegeta agreed and they did the fusion dance. The first time though they got it wrong and turned into fat Gogeta a form which is extremely weak but can take a lot of damage. Janemba used him as a punching back so to speak and fat Gogeta was on the run the whole time and then finally the fusion wore off and they went back to there old selves.

They then agreed to do the fusion dance again but did not believe there would be enough time but Pikkon came down and agreed to fight Janemba while they fused and just as Vegeta and Goku fused into the real Gogeta Janemba hit Pikkon hard on the top of both sides of his head making him fall out. When Vegeta and Goku turned into Gogeta there every attack landed perfectly on Janemba and it seemed as though he was a mere child to there strength. Then Gogeta raises his hand and a weird colored ball appeared and it turned into a tiny ball and it went into his hand. Seeing this Janemba attacked Gogeta by punching him in the face and while he punched him in the face Gogeta threw the energy right through Janemba's stomach killing him. After Janemba died the person who was turned into Janemba came back and everything was returned to normal. Then Vegeta left and bid farewell to Goku and back on Earth Trunks and Goten claimed to know what happened but said they would not tell and Shenron was still there waiting for a wish.