Goku is surprised that all of his friends are alive, stating that he was sure Freezer would have "Yamcha'd" at least one of them before greeting Yamcha. Goku then asks who killed Freeza, and Vegeta tries to regain some credibility before Bulma tells Goku that Trunks was responsible. Trunks asks to speak with Goku in private, and he agrees, to Gohan's dismay, as it's been almost two years since they last saw each other. Trunks accidentally refers to Goku as Sun Wukong, but Goku doesn't seem to notice this. Trunks asks Goku about his fight with Freeza and asks to see his Super Saiyan form. Goku agrees despite having never met Trunks, and shows him his transformation. Trunks follows suit and also transforms. Goku is surprised that Trunks' hair is yellow, and he is shocked when Trunks tell him that his hair is also yellow.
The onlookers compare the two and conclude that Trunks is a Super Saiyan before being cut off by Vegeta. Krillin compliments Tien about his appearance and he jokingly states that he might be the next Super Saiyan, to Vegeta's annoyance. Goku sees that Trunks is a Super Saiyan and asks if anything has happened to Krillin while he was gone. Trunks tries to attack Goku, but he is completely indifferent to these attacks and continues to ask about Krillin. Trunks decides to tell Goku his secret, and Goku swears on Krillin's life that he will keep it. Trunks is uneasy for obvious reasons, and Goku decides to swear on Bulma's life. This prompts Trunks to accidentally reveal that Bulma is his mother. Goku then unintentionally realizes that Vegeta is the father, much to Piccolo's amusement. Goku prepares to congratulate the two, but Trunks reveals he's from the future. He gives out a warning about two creatures that will arrive on May 3rd, 900 miles from South City three years from now, created by the defunct Red Ribbon Army. Goku quickly realizes that he means "androids", even though the correct term is cyborgs. Trunks also reveals that they killed Vegeta, Piccolo, Tien, Krillin, and Chiaotzu. Yamcha died as well, but from suicide, after learning about Bulma's pregnancy with Vegeta. Goku asks about himself, and Trunks reveals that in two years he will die of heart failure from too much bacon, which Goku doesn't believe, but he gives Goku medicine that will level his cholesterol. Goku then questions if the medicine is grape flavored, which surprisingly isn't his favorite flavor, and Trunks lies that it's bacon flavored.
After Trunks returns to the future, Goku tries to tell everyone what Trunks told him but needed help from Piccolo on the details. He also reveals that the muffins from the Muffin Button protected him from the explosion of Namek and took him to planet Yardrat where he learned how to use Instant Transmission, from eating the sick. The Z Fighters afterward go their separate ways to train. Chi-Chi scolds Goku for leaving with Gohan, and she also refuses to make dinner for him. Goku and Piccolo constantly try to drive cars instead, in-between training with Gohan and leaving him at the bottom of the cliff, where Goku states that Gohan needs to learn to dodge.
Meanwhile, back at CapsuleCorp, Vegeta requests that Dr. Briefs make him a spaceship with a gravity chamber that can go 500x's the Earth's gravity. Dr. Briefs reluctantly does so, but Vegeta's first outing goes bad, and the ship explodes. Despite his injuries, Vegeta continues to train. Bulma interrupts Vegeta's training, arguing that he shouldn't be training with injuries, only for the two of them to trade insults with each other. Finally, Bulma tells Vegeta to meet her in her bedroom, where they have sex. After they have sex, Bulma asks Vegeta where his condom is, to which Vegeta replies that he has no idea what that is.
The stinger consists of Piccolo and Goku driving cars. They hit each other's cars and crash with "the dodge bitch get out the way bitch get out the way" song playing in the background.
- MasakoX – Gohan, Goku
- Faulerro – Yamcha
- Lanipator – Vegeta, Piccolo, Krillin, Master Roshi
- Megami33 – Bulma, Chiaotzu
- KaiserNeko – Trunks
- Ganxingba – Tenshinhan
- Hbi2k – Nail, Dr. Briefs
- LittleKuriboh – Narrator
- Hnilmik – Chi-Chi
- Takahata101 – Tama
- Trunk's time machine is a reference to the TARDIS from Doctor Who.
- Trunks calls Goku Sun Wukong by accident in which Son Goku and Sun Wukong are actually the same (Sun Wukong is the original Chinese version of Son Goku). Goku appears to be aware of this, which could explain why he didn't correct Trunks when he said it.
- It also refers to the main character 'Sun Wukong' from the Chinese story 'Journey to the West', which was also the basis for Dragon Ball. Sun Wukong was also the inspiration for Goku.
- It might also refer to the hospital Goku was in after his battle with Vegeta (without Sun).
- The first episode where "fuck" is uncensored, where Vegeta asks Bulma the condom.
- The title is a reference to the famous X-Men storyline, Days of Future Past.
- Trunks' parting comment to Goku of "Until we meet again!" may be a reference to the final spoken words in the last episode of Dragon Ball GT, the last words spoken chronologically in the Dragon Ball GT universe.
- The songs Goku and Piccolo sang while driving were parodies of AC/DC's "Highway to Hell' and Ludacris' "Move Bitch" respectively.
- The way Goku learns Instant Transmission is different than the original source material. In the original, he was trained by the Yardrat's while waiting for his ship to be repaired. In Team Four Star's version, Goku was fed their sick and somehow learned how to use the technique.