Digimon Adventure:

In 2020, technology is deeply woven into daily life, with all digital devices linked by a vast global network. Unknown to humanity, this network has given rise to living creatures called "Digimon." Taichi Yagami, a fifth-grader getting ready for summer camp, notices odd disruptions in Tokyo-electronics malfunctioning without explanation. When he learns his sister and mother are stuck on an out-of-control train, he rushes to the station. Without warning, Taichi is pulled into another world where he meets a peculiar creature named Agumon, who strangely knows him already. He also receives a mysterious "Digivice," a device that lets him stay connected to the real world. Taichi realizes he’s inside the "Network," where virus-like Digimon are wreaking havoc on the systems that keep Tokyo running. Now, he and Agumon must work together to stop these digital threats before the chaos spreads beyond the city and endangers the entire world.