Tai is now a university student, living alone, working hard at school, and working every day, but with his future still undecided. Meanwhile, Matt and others continue to work on Digimon incidents and activities that help people with their partner Digimon. When an unprecedented phenomenon occurs, the DigiDestined discover that when they grow up, their relationship with their partner Digimon will come closer to an end. As a countdown timer activates on the Digivice, they realize that the more they fight with their partner Digimon, the faster their bond breaks. Will they fight for others and lose their partner? The time to choose and decide is approaching fast. There is a short time before “chosen children” will become adults. This is the last adventure of Tai and Agumon.
Upon arriving at the Digital World after the "reboot", the digidestined are hunted by a new villain. Meanwhile, Sora is troubled by her partner digimon's indifference towards her.
The DigiDestined go to a nearby hot springs theme park and everyone has a good time, but Joe doesn't show up because he wants to study for his exams. Another infected Digimon, Ogremon, attacks Odaiba. Gomamon runs away from home while Mimi faces problems with the other DigiDestined and her classmates because of her selfish ideas.
Digimon Adventure 3D: Digimon Grand Prix! was first shown in July 2000 in Sanrio Puroland and in Sanrio's character theme park Haromy Land. The movie was later rerun at Toei's anime festival "Tobidasu! 3D Toei Anime Matsuri" on 03.10.2009. Together with Digimon Savers 3D: Digital World Kiki Ippatsu!, and 2 other CG anime works by Toei, it was released on DVD on 21.02.2010.