Digimon Adventure:

Taichi is in fifth grade and preparing for a summer camping trip when a large-scale network malfunction occurs. Taichi's mother and his younger sister Hikari get stuck on a train that won't stop moving, and Taichi heads to Shibuya in order to help them. However, on his way there, he encounters a strange phenomenon that sweeps him up into the Digital World along with the other DigiDestined.