It's the year 2020. The Network has become something humans can no longer do without in their daily lives. But what humans don't know is that on the other side of the Network is the Digital World, a realm of light and darkness. Nor are they aware of the Digimon who live there. Fifth grader Taichi Yagami]s mother and little sister Hikari went to Shibuya, and now they're aboard a runaway train. Taichi hurries to Shibuya to save his mother and sister, but the instant he heads toward the station platform... a strange phenomenon befalls the DigiDestined, and Taichi goes to the Digital World!

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.

After years of inactivity, the DigiDestined regroup with their Digimon to save their world, but have the years changed their characters too much?

The Digital World is becoming so overpopulated that the super computer Yggdrasill who governs the Digital World can no longer handle it. Its solution is Project Ark: to wipe out most of inhabitants with the X Program. Yggdrasill chooses a very small percentage to be moved to a new Digital World and then proceeds to destroy the old one. Some Digimon who were not chosen survive anyway, and they move to the new world with a rare gift known as the X Antibody; this antibody changes their appearance and makes them more powerful, while at the same time making them immune to the X Program. No longer in control, Yggdrasill uses the Royal Knights to destroy these X-Digimon, who are outcasts in the new Digital World.

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.

A year after the events of the first season, a virus Digimon called Diaboromon appears and starts attacking the Internet. The children and their Digimon unite once more in order to prevent him from destroying every communications network on the planet.