Learn to Fuse! (Gohan Fukkatsu!! Kaioshin no Himitsu Heiki!? 悟飯復活 界王神の秘密兵器!?) is the eleventh episode of the Majin Buu Saga and the two hundred forty-second overall episode in the original dubbed and the uncut Dragon Ball Z series. The episode first aired on October 12, 1994. Its original American air date was September 23, 2002.
The episode begins as Majin Buu literally blows up the now vacant city. Babidi then informs the people of Earth that if Goten, Trunks and Piccolo are found, to tell him or he and Majin Buu will destroy the Earth in 5 days. Marvin, a World Martial Arts Tournament staff member, informs Babidi of the names of the ones he is searching for, but Babidi finds the information useless and blows up his head. At Kami's Lookout, a very angry Piccolo has heard the news that the world will be destroyed in five days by Majin Buu, and offers to give himself in. He then decides to stay and help Goku teach the boys the Fusion Dance. Meanwhile, Trunks and Goten awaken and go off to explore.
On the Sacred World of the Kais, Gohan is healed and Gohan believes that he is dead, but realizes that doesn't have a halo like his father and Kibito informs Gohan that no mortal has ever set foot on the sacred world before and Gohan points at Kibito that he really is dead, but the Supreme Kai tells him no and that it was a close call. The Supreme Kai tells Gohan that he was brought there to pull out the legendary Z Sword, which has never been done by anyone. The Supreme Kai explains the sword makes its owner unbeatable. Kibito totally doubts that Gohan can pull out the sword and thinks it was a mistake bringing him to the planet in the first place. The three of them rush off to find the Z Sword.
Goten and Trunks awake on their own. They swiftly become restless and decide to go exploring. They are encountered by Mr. Popo who startles Trunks. The two young boys then go about attacking Mr. Popo, not knowing who he is, or what he wants with them. Eventually, Goku comes across the three of them, and reassures the two boys that they are safe.
Gohan, the Supreme Kai and Kibito fly towards the Z sword. Kibito makes a comment on Gohan's current apparel, stating that its not nearly suitable enough as Gohan cannot train in dirty old rags. Kibito then provides Gohan with clothes similar to their own. Supreme Kai and Kibito then gives Gohan his first task is to pull out the Z sword and Gohan decides to give it a try.
Back at the lookout, Trunks and Goten are found crying after Goku tells them of Gohan and Vegeta's death. Goku takes a much sterner approach, stating that there is no time for tears, and that they need to suck it up if they are going to be able to stop Majin Buu. The others watch in anticipation as the two boys stop crying and prepare for the lessons ahead. The episode ends with Gohan, knelt beside the Z Sword, preparing to pull it out.
- Majin Buu destroys and entire city on Babidi's orders.
- Gohan is taken to the Scared World of the Kai where he is healed.
- Shin tells Gohan about the Z Sword and takes him to it.
- Mr. Popo vs. Trunks (Super Saiyan) and Goten (Super Saiyan)
Bruce Faulconer tracks
- "Frieza Begs" - When Vegeta knocks out Trunks and Goten.
- "Trunks and Goten" - When Trunks and Goten fight Mr. Popo.
Differences from the manga
- Trunks and Goten waking up and wandering around The Lookout not knowing where they are is exclusive to the anime.
- A subsequent scene of them eating an meal before they are confronted by Mr. Popo and attack him in return before being stopped by Goku is exclusive to the anime.
- When Babidi shows the Earth who he is looking for, Goten and Trunks are seen in their base form even though Babidi only saw them as Super Saiyans.
- Trunks telling Goten there is food to wake him up is reminiscent of Bulma's trick on Goku during the Dragon Ball episode "Number One Under the Moon?".