You're Calling This Uncool?! The Fusion Pose Training!
With the threat of Babidi changed, Majin Buu sets off on an unhinged rampage across the Earth. Facing a rapidly diminishing deadline for his time in the living world, Goku places the fate of the planet entirely on Goten and Trunks. To prepare the young Saiyans for the battles ahead, Goku begins instructing them on the precise physical movements required to execute the Fusion technique.
Aired 02/11/2014EP 30 - You're Calling This Uncool?! The Fusion Pose Training!
Dragon Ball Z Kai: The Final Chapters
Since Cell's defeat Gohan has grown up and go to the university then she meets Videl which who has some adventures, then both and his new brother Goten are training for the new tournament, in which Goku came back from the dead for one day. In half of the tournament a misterious persons advice the group about the resurrection of the dangerous Majin Boo, but all plans fails and every one try new ways to stop The dangerous Majin Boo who gets stronger each time. Goku and his friends make everything for stopping them through fights.
(Source: Anime News Network, edited)
Note: Remastered version of the Majin Boo arc that adheres more to the manga's story.