Rescuing Gohan and Company! Goku and Vegeta's Infiltration Mission!
Having been drawn into Majin Buu's body, the Saiyan warriors navigate a bizarre and hostile internal environment to locate their trapped allies. As they work to undo the monster's past victories from within, a sudden complication threatens their team dynamics. Meanwhile, freeing the captured fighters sets off a volatile reaction that drastically alters Buu's very existence.
Aired 12/04/2015EP 50 - Rescuing Gohan and Company! Goku and Vegeta's Infiltration Mission!
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.