"My sincerest gratitude to all those who bought this Dragon Ball GT DVD box. Being a lazy bum by nature, I was absurdly happy when I managed to safely finish up Dragon Ball’s serialization, and finally be released from Deadline Hell. The TV anime people wanted to continue for just a little bit more, but I [just couldn’t do] any more than that… And so, I left the Dragon Ball anime completely up to the anime staff, story and all. That was Dragon Ball GT.
In car lingo, GT means “Gran Turismo”: a fast, high-powered car, in other words. But in this case, I had GT mean “Grand Touring”, a great journey, since the scenario was that they’d be running around the universe.
For GT, all I did was just come up with the title, design the initial main cast and some of the machines, and also do a few images. However, I was able to rest easy handing things over to the excellent staff, who had continued on Dragon Ball for all this time. In particular, the animator Nakatsuru-kun is amazingly skilled, and mastered the peculiarities of my drawings in no time at all, to the point where there were even times when I couldn’t tell whether I had drawn a certain character design, or if he had. For instance, one of Nakatsuru-kun’s designs was “Super Saiyan 4″, which appears in GT, and the picture above is a portrait that I drew looking off it. Did I draw it well?
Dragon Ball GT is a grand side-story of the original Dragon Ball, and it’ll make me happy for us to watch and enjoy it together."
— Akira Toriyama
He drew this for the GT Box set for example.
Furthermore, Dragon Ball GT was an anime created by the makers of the DBZ anime, supervised, strictly overseen, and designed by Akira Toriyama. Though a loud minority of fans seem to think it is not part of the series, this is not actually the case.