While the chosen ones are on summer vacation in the real world, Koshiro discovers a virus on the Internet that infects a Digi-Egg: a corrupted Digimon that rapidly digievolves and takes over the Internet world.

When Taichi finds out about it, he wishes that Agumon was there. Before Mamoru Hosoda made a name for himself in the anime world, he directed several sequels in the Digimon saga for Toei Animation, including this mid-length feature.