Reunions (史上最強の戦士は悟空の兄だった!, Shijō Saikyō no Senshi wa Gokū no Ani Datta!; lit. "The Strongest Warrior in History is Goku's Older Brother!") is the second episode of the Raditz Saga and the entire Dragon Ball Z series. Its original Japanese air date was May 3, 1989. Its original American air date was June 15, 2005.
After being away for five years, Bulma is invited to Kame House, where Master Roshi and Krillin have been living. Goku arrives shortly, and introduces his son, Gohan, to everyone. Master Roshi points out that Goku named him after his Grandpa Gohan. Bulma is impressed with how proper Gohan's speech is, in light of who his parents are. Goku tells her how Chi-Chi is quite strict about the education Gohan receives, and how she does not let him train Gohan.
Everyone then realizes that Gohan has a tail, and collectively worries, but after a delicately-worded question to Goku, they are relieved to hear that his family goes to bed early, not giving Gohan a chance to ever see a full moon. Master Roshi is surprised at how Goku still has a lot of strength, especially considering his having settled down with a wife and a child. Bulma also sees that there is a four-star Dragon Ball on his hat and reminds it about her quest finding the Dragon Balls with Goku. Krillin asks Goku what he should wish for if he collects all seven Dragon Balls while throwing some stones at the ocean and Goku says that he doesn't know and throws a stone at the ocean.
Before they go inside, however, Goku senses a strong presence headed their way. They think it's Piccolo from the 23rd World Martial Arts Tournament five years ago, but it's not Piccolo. The alien soon appears. Krillin, unaware of the strength the alien possesses, attempts to show him off the island. Raditz knocks Krillin through the side of Kame House with his tail. Raditz identifies Goku as Kakarot and berates him for not completing his "mission". Further complicating matters, Raditz also claims that Goku is a Saiyan warrior, and that he and Goku are, in fact, brothers.
Goku and Krillin understandably think that Raditz is insane, but Master Roshi reveals that there may be some truth to the evil Saiyan's words.
Master Roshi reveals that Goku's adopted grandfather, Gohan found a strange space capsule in the woods, containing a baby Goku. He explains that, as a baby, Goku was violent and ill-tempered. Nevertheless, an accident caused him to fall and hit his head, causing a case of amnesia in which Goku forgot about his original Saiyan programming which, in turn, changed Goku into the happy, amicable child that everyone came to know and love.
This new revelation shocks Goku, who refuses to believe its validity. Raditz then goes on to state that Goku's original purpose was to destroy all life on Earth, which he should have done in a matter of years after his arrival. Raditz also reveals that the Saiyans' original home planet, Planet Vegeta was destroyed by an asteroid sometime after Goku's departure to Earth and that there are only four Saiyans left, including himself and Goku.
Finally, Raditz mentions that he needs his brother's help in destroying all life on a distant planet. Goku refuses, which prompts Raditz to notice Gohan, who still retains his Saiyan tail, which leads Raditz to threaten the fate of the child. Goku tries to stop him, but is dealt a powerful knee strike to the stomach, which sends him plummeting to the ground. Raditz then kidnaps Gohan, and tells Goku to kill one hundred Earthlings, if he ever wishes to see his son again.
- There is a timeline issue with this episode and Dragon Ball Z: Dead Zone. The Dead Zone movie is supposed to have happened before this episode (between Dragon Ball and Dragon Ball Z) but Krillin acts like he has never seen Gohan before, when he actually has met him in the Dead Zone movie. See Dead Zone continuity.
- When Raditz is speaking to Goku and the gang, he makes a reference to the history of Planet Vegeta, saying "3 years ago, our planet was destroyed by meteorites", but assuming Goku grew up as fast as a human, this is incorrect. Furthermore, as it is stated in the series that around 12 years have passed since the beginning of Dragon Ball, Raditz's statement is clearly inconsistent. This exists in the original Japanese manga and all dubbed versions of Dragon Ball Z, but it was changed in the dub of Dragon Ball Z Kai.
- In the beginning when the Narrator is explaining what happened in the previous episode it is heard that Piccolo was the first to meet Raditz face to face, this is not true though, as he in fact met the farmer with the shotgun first.
- In the edited version of the series, Dragon Ball Z Kai, Gohan states that he wants to be a scholar, but in the original series in this episode he states that he wants to be an orthopedist.
- Both Vegeta and Nappa make cameo appearances in this episode when Raditz tells Goku and his friends about the Saiyan race and what they do.
- Goku being attacked by Raditz with Heavy Finish, is a similar pain to how he felt when he had the heart virus, as well as Future Goku later on in the Androids saga.