Picking up where we last left off, Gotenks could no longer sustain Super Saiyan 3 and his time is almost up. Old Kai admits that they finished the ritual for Gohan's sleeping powers about 5 minutes ago and tells him to act as if he were transforming into Super Saiyan. After powering up, Gohan looks like he's still in his Normal Form but his eyes are drawn differently compared to before, supplementary material refers to this state as "Ultimate Gohan" but many fans also call this state "Mystic Gohan". Many fans also debate about whether or not Ultimate Gohan counts as a transformation. After Goku & Gohan say goodbye to one another, Kibito teleports Gohan to Earth and uses the "clothes beam" to give Gohan his father's gi before returning to the Planet of the Kais.
Eventually, Gotenks' time expires and Piccolo prepare to fight alongside the boys...but Super Buu ends up falling asleep. Piccolo is cautiously thankful about this and has to warn the boys not to do something foolish, such as seeing if Super Buu is really asleep. Gohan eventually arrives, explaining where he has been all this time and how he survived, just as Super Buu awakens. After being told what happened to their family friends, the episode ends with Gohan declaring he will kill Super Buu.
I always found Goku & Gohan's goodbye to be rather heartwarming, especially after the "Goku is a bad dad joke" became more prevalent; I always appreciated those moments that show Goku does care about his family and friends even with his flaws. I also remember all the debates on whether Ultimate Gohan/Mystic Gohan counts as a transformation or not, many fans can't seem to agree on that point. It will be interesting to see the DBZ Kai Version of Gohan's fight with Super Buu in action.
I also liked that moment between Goku and Gohan, as well as Gohan finally wearing the classic gi for the first time* since before Vegeta and Nappa's arrival. Goten and Trunks' resolve to join Gohan even while weakened was sweet and almost makes up for their stupidity in trying to wake up Buu. Almost.
Is it me, or is this actually the last time Goku and Gohan showed an affectionate gesture to each other in a peaceful situation? I suppose it is a coda to that first-ever (manga) scene of Goku holding Gohan in his arm (with the kid clutching his Gi).
Let me post Goku's words of wisdom here because they belong here:
"You can't get us our future! We've got to fight for it ourselves, or we won't treasure the world we've got! We'll take it for granted! Struggling, really earning it...that's the only way we'll appreciate being alive!"