The story takes place in 2020, where the network has become essential in human lives.
Humans have yet to know what's on the other side of the network, the infinite world, the digital world, and the Digimons that are living there.
A large-scale network failure occurs in the Tokyo metropolitan area, causing a chaotic flickering of signals and corrupted texts everywhere.
The news report that it's cyber terrorism.

Taichi Yagami, a fifth-grade elementary student living in a tower apartment near Tokyo, was left home alone to prepare for a summer camp on the weekend. After knowing that the train his mother and sister Hikari are riding on to Shibuya could no longer stop, Taichi rushes to Shibuya to save his mother and sister, but the moment he heads for the station platform...

A mysterious phenomenon occurs to the "Chosen Children" and Taichi enters the digital world!
The children meet their partner, Digimon, and ready to face a new and unknown "adventure"!