Two children receive a strange egg that hatches into their very first Digimon, leading to the night that would change their lives forever.

Months after the events of the first season, a 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.

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.

In this movie, that takes place three months after MaloMyotismon's defeat, the DigiDestined go up against Diaboromon again. Tai and Matt head back to the Internet to deal with him with Omnimon, while the younger Chosen Children go to deal with the rampage of a swarm of Kuramon (Diaboromon's Fresh form). With the help of Angemon and Angewomon (with T.K. and Kari), Omnimon was able to destroy Diaboromon again, but it turned out to be a trap, as his destruction allowed many more Kuramon to go to the Real World. Things go out of control when the Kuramon in the Real World merge to create a Mega level called Armageddemon, an alternate Mega in Diaboromon's evolutionary line. It is so powerful that neither Omnimon nor Imperialdramon were able to defeat it on their own.