The events of Battle of Gods take place several years after the titanic battle with Majin Buu, which determined the fate of the entire universe. Goku has come to King Kai's planet in order to train. Old Kai, Kibito Kai, and King Kai are telepathically discussing Bills' early awakening. While Goku is running with Bubbles, he notices King Kai is discussing something interesting and then learns about Bills, a God of Destruction tasked with maintaining balance in the universe. Goku says that he wants to battle Bills, and King Kai scolds him.
Meanwhile in Bills' temple, the mysterious Whis is walking slowly with a serious look. Alarm bombs explode, but Bills still does not wake up. Whis tells him to get up now, as he cannot sleep-in another 15 years like he did before, and threatens to perform an "awakening song" if Bills does not get up now. Terrified, Bills gets up right away and slides down from his bed atop a floating rock. He is still cranky because he only got to sleep for 39 years this time, which is barely an afternoon nap. Whis points out that Bills was the one that set this as the time of his next awakening, and asks him why he even wanted to get up this early anyway. Bills, now cleaning his fur, says that he was concerned about something in this era...
As he eats breakfast, Bills asks Whis if Frieza destroyed Planet Vegeta while he was asleep. Whis confirms that he has, and not a trace of the planet remains. Bills is glad to hear this, as he did not care much for the people on that planet, particularly King Vegeta. He could have destroyed the planet himself, but it was so far away, and he did not want to bother. On the other hand, Bills does not like Frieza that much either, since he is evil and so very full of himself, and decides on destroying him next. However, Whis informs Bills that Frieza has already been defeated, by the Saiyan, Goku, who is otherwise known on Planet Vegeta as "Kakarot". While most of the Saiyans were destroyed, along with Planet Vegeta, a few survived and are living on other planets, including Prince Vegeta. Bills is surprised that anybody else could defeat Frieza, let alone a saiyan. Whis further explains that the surviving Saiyans have acquired the ability to transform into "Super Saiyans". That phrase rings a bell with Bills, but he cannot remember where. It then comes to him that he dreamed of fighting something awfully similar while sleeping: Super Saiyan God! He is convinced this must have been a prophetic dream. Umimpressed, Whis points out that Bills's "Prophetic Dreams" have been terribly unreliable in the past.
To settle the matter Bills consults the Oracle Fish, asking her if 39 years earlier, the Oracle Fish foretold that a mighty opponent would appear before Bills. The Oracle Fish does not remember it, but Bills is convinced that it said so. Bills then tracks down the warrior who defeated Frieza, Goku. On King Kai's planet with Whis, Bills complains that the planet is so small, but Whis reminds him that he is the reason it is so small for destroying it when getting mad after losing at hide-and-seek. Bills questions Goku about the Super Saiyan God and Goku demonstrates the various Super Saiyan levels that he is capable of utilizing, but he has never heard the Super Saiyan God form. However, ecstatic over the new challenge, Goku does not heed King Kai's advice and battles Bills. Super Saiyan 3 Goku then engages Bills, but his attack is effortlessly blocked. Goku is then tossed and finally sent flying into the ground by a mere flick to the head. Now seemingly angry, Goku charges once again, but Bills repeatedly dodges and blocks Goku's attacks and even effortlessly evades a mighty punch that subsequently blows straight through King Kai's planet. Bills' incredible speed then allows him to come up behind Goku, and he defeats him with a single carefree chop to the neck, rendering him unconscious and causing him to revert back to his base form. Disappointed by the subsequent lack of challenge, Bills departs in order to see if the Saiyan Prince Vegeta and the other Saiyans on Earth know more about the Super Saiyan God. King Kai curses Goku for his foolness.[2]
At Capsule Corporation, Bulma's birthday party is being held when the God of Destruction's arrival erupts the party. It appears that Vegeta already knows Bills:[3] Vegeta was in a training session when King Kai contacted him about Bills, and he did not even join Bulma's party and did not care anyway that Bills was coming and willl wipe out Earth, until King Kai informed him that Bills took out Super Saiyan 3 Goku in just a few blows. After the transmission, Goku wakes up, almost completely wounded. Meanwhile back on Earth, Terrified at what happened, Vegeta goes to warn everyone about Bills. However, when he arrives to warn his friends, Bills is already there, so Vegeta has to immediately start playing party-host instead. Vegeta musters all of his excitement and casts aside his pride to put the party's unannounced attendee in a good mood, while the Z Fighters and their friends are enjoying leisure activities;[3] Piccolo sings karaoke and a game of bingo is held with a pretty girl unveiling the prices, with one of them being a castle and another one being the complete set of Dragon Balls. Bulma just wanted to have a reason to see everyone and she has a special prize for the Bingo game, as she knew everyone would get together if she had a special prize.[4] Bulma says she is 38, but even Krillin is skeptical when he hears the number. The Pilaf Gang sneak into the party in order to steal the Dragon Balls, but Bulma does not recognize them because they have been turned into children;[3] before the events of the film, they gathered all the Dragon Balls themselves and wished for youth, but Shenron made them a little too young.
Bulma invites them to the party as a result. When Trunks claims that Mai is his girlfriend just to boast to Goten, everyone takes it seriously and Mai gets shy. When they ask how old she is, Mai says she is 41, making them laugh. Emperor Pilaf remembers when Great Ape Goku destroyed his castle when he sees Goten's hair is similar to that of Goku. A drunk Gohan appears as Great Saiyaman[5] and he asks Mai to shoot him. He snaps all the bullets with one finger, but one of them hits Videl's leg and another one hits Bills' forehead. While healing her, Dende notices that Videl is pregnant. Videl has been hiding the fact to surprise Gohan later, and Dende does not reveal it to the others yet.
Bills, who was hit by a stray bullet, decides to destroy Earth, saying "Before creation comes destruction" he charges up the attack. But Vegeta interrupts, saying that the Bingo Tournament is just beginning. Vegeta desperately does a song and dance about bingo, which convinces Bills and Whis to go on eating for a while longer. Others start to wonder why Vegeta is acting so strange. Bulma forgives the Pilaf trio's misbehavior and collects the Four-Star Ball from them for the tournament. As the others play bingo, Whis tells Bills that there is supposed to be some great custard pudding. In fact, Majin Buu is eating some now. Bills asks Buu for one and Whis asks for two, but Buu says he is going to eat them all himself. Bills cannot believe Buu will not share when he has so many, but Buu shouts back at him saying they are all his and proceeds to lick them all. Bills struggles with Buu over the pies, until Buu tries to turn him into candy.
Vegeta finally notices what is going on and curses himself for letting Bills out of his sight. It is too late: Bills finally snaps, saying he will destroy the Earth for this, and unleashes his power in a fit of rage. Mr. Buu rushes at Bills, but is sent flying off into a lake with a mere kai. Vegeta asks Bills to stop, but Roshi announces their attack. Android 18, Tien Shinhan and Piccolo attempt to fight Bills and the God of Destruction easily defeats them one after another.[3] #18 is knocked out by a single elbow strike to the neck, Tien's attack is halted by a pair of chopsticks Bills pick up from a table, using them to catch his fist and toss him, and Piccolo is rendered unconscious from two swift pressure point strikes to the body by Bills' chopsticks. Bills then retrieves Buu from the lake, and meanwhile Gohan powers up and attacks Bills only to have his full-nelson reversed and his head slammed into Buu's. Gohan is then taken down by a heavy kick to the abdomen from Bills, and Buu is smashed back down into the lake. Goten and Trunks perform the Fusion Dance to form Gotenks, and attempt to fight Bills but he is quickly defeated as well. Vegeta decides to fight Bills on his own after the other Z Fighters have been defeated. Meanwhile, Whis enjoys sushi in a restaurant near Capsule Corporation, not even bothering to watch the battles unfold, and a motorcycle policewoman observes the battle at Capsule Corporation from a distance.
Vegeta is ultimately defeated and has admitted defeat at this point, and Bills is about to finish off Vegeta, but then Bulma walks up and scolds Bills for ruining her birthday party, slapping him. The God of Destruction returns the favor right back and responds with a slap of his own, only his is much harder. Seeing his wife being beaten, Vegeta explodes in a fit of rage. He powers up, shouting "How dare you did that to my Bulmaaa!!!", and he starts knocking Bills around for a bit. Watching the battle, Master Roshi says in amazement Vegeta's power in that moment seems to have surpassed that of Goku. Vegeta's anger gives him incredible power, but as soon as his rampage is over, Bills is just fine and Vegeta once again accepts his and the planet's fate as Bills pokes Vegeta in a forehead, knocking him and rendering him unconscious.
It is revealed that Goku was there watching Vegeta's battle against Bills, and he did not intervene because he wanted to watch Bills in action in order to form some kind of strategy. Goku decides to use the Dragon Balls and ask Shenron how to reach the Super Saiyan God form. He and his friends summon Shenron, and the dragon says that a Super Saiyan God once appeared on Planet Vegeta to stop evil Saiyans, but he failed because of the form's time limit. The dragon also reveals that they need the power of six pure-hearted Saiyans for one of them to reach the Super Saiyan God form. With Vegeta, Gohan, Trunks and Goten's help, Goku's power gets way bigger, but Piccolo says that rather than becoming a god he has just gathered up everyone's power and he can not win like that. After this failed first attempt at creating Super Saiyan God, Vegeta's younger brother is mentioned when Goku and his friends realize that they need a sixth Saiyan, but they do not know how to contact him, but Videl then reveals to everyone that she is pregnant. Goku eventually transforms into a Super Saiyan God, a form beyond even Super Saiyan 3,[6] thanks to the power of himself, Vegeta, Gohan, Trunks, Goten, and Pan from inside her mother, as she was not born yet, fulfilling the prophecy once stated by the Oracle Fish.
Goku confronts Bills again and they wage an intense battle in space, right above planet Earth. The form gives Goku the power to resist Bills, but he reverts back to his regular Super Saiyan form due to the form's time limit. However, he learns the form's godlike feeling, which allows him to use Super Saiyan God's power against Bills. Bills points out to Goku that Super Saiyan God's time limit ran out some time ago and that Goku did not notice because he was able to absorb the Super Saiyan God power into his body while he was fighting. Bills says that because of this, Goku did not greatly power down even after returning to normal. Goku did not feel quite satisfied because he could only reach that level of power with everyone else's help rather than on his own, so Goku feels contented becoming able to fight at a level not too far removed from Super Saiyan God all on his own. The two seem to be equally strong at some point, but Bills eventually wins when he uses his God of Destruction Super Energy Sphere. Goku stops Bills' energy sphere, barely holding it back, and the screen suddenly blacks out. Chi-Chi and Goku's friends appear in Goku's mind, then he briefly transforms to Super Saiyan God again and absorbs the energy ball. Goku gets exhausted, and Bills decides to stop the fight, only if Goku will say "I give up", Goku obliges and surrenders, saying he is no match for Bills, whose strength is just what you would expect from the best in the universe.
Bills says that Goku now finally understands the ferocity of the God of Destruction. Still, he says Goku was plenty strong himself. In all of Bills's long history of fighting, Goku was the second strongest person he has ever fought. Goku laughs, but is curious why he is only number two. Bills says he has one more thing to tell him. Goku expects him to give up on destroying the Earth, but Bills says his principle is to not change his mind once he has decided on doing something. Actually Bills wanted to tell Goku about Whis. While Whis is Bills's attendant, he is also Bill's martial arts master. Goku cannot believe it. This must mean that the real strongest in the universe is... Whis?! Bills continues, saying this world is the Seventh Universe. Bills explains that he is the God of Destruction for the Seventh Universe, but there are twelve universes in total. Goku cannot help but laugh at the prospect of there being even more incredible people. He finally collapses out of exhaustion and everyone panics, but Gohan confirms that he is still alive. Bills says he will destroy the Earth now, just as he promised. He fires off another fearsome-looking attack, which destroys... a small rock. Whis wonders why Bills only destroyed such a small part of the earth, and Bills responds that he seems to not any stamina left. He will just have to destroy the rest of Earth next time.
Whis asks Goku if he would like to be the next God of Destruction after Bills dies, but Goku turns him down. Bills apologizes to Bulma for hitting her. Bulma says she would be glad for them to attend her next party, but only if they promise not to cause any trouble. Bills understands, though next time they had better make sure he gets to eat some custard pudding. Bulma promises she will prepare a bunch just for him, but he had better not say they taste bad. Bills says that if they do taste bad, he will destroy the Earth for sure that time. Goku says if he tries, then they will just have to fight again. Bills and Whis bid everyone farewell and depart off to space From the Sacred World of the Kais, the Supreme Kais comment on Goku befriending the God of Destruction. After they return home, Bills tells Whis that both Goku and Vegeta might become formidable foes before long. Whis explains to Bills about soy sauce and wasabi, which he learned about while Bills was busy fighting. Bills tries some of the wasabi, which turns his face red and he shoots up into the air in extreme pain. Whis rushes over and karate chops Bills to put him to sleep for another three years, but then tells Bills to brush his teeth before going to bed.
On Earth, while Bulma's birthday party continue, Vegeta says that he will be Super Saiyan God next time. When Goku reveals that he was on Earth watching the battles, he says that Vegeta became an incredible Super Saiyan back when Bills slapped Bulma and even jokes that they should just have their enemy hit Bulma the next time they are up against some nasty opponent, only for Bulma to slap Goku. Goku needles Vegeta about shouting "How dare you did that to my Bulmaaa!!!" when defending her against Bills, and Vegeta denies that he said such a thing. Piccolo then says that Goku must have been watching back during that fight, and everyone gets mad at Goku for not helping out then. Oolong, upon hearing this, jumps on Goku yelling at him about their lives being in such grave danger. Goku says he wanted to scout out Bills to try and form a strategy, but ultimately it did not help at all. Vegata tells Bulma to slap him again, which she agrees to do with pleasure. Goku starts crawling away as Bulma winds up...