Episode 0Humans have begun arriving in the Digital World, either through Labyrinth Events or through the shut down of the VR MMORPG "Digital World", over a period of three months.
Three months ago, a mysterious event dubbed the "Labyrinth Event" by mass media occurred in Yoyogi Park, part of Tokyo's Shibuya district. Though the park was quickly evacuated and closed to visitors, news media, eyewitnesses, and social media posters insist that parts of the park were "digitized"—sections of the ground became code or translucent polygons, and most notably of all, people report seeing unusual creatures. Some have chalked the event up to mass hysteria, but most agree that something unnatural occurred that day.
Two weeks later, the Digital World game had server maintenance meant to correct a problem with the game. People who forgot to log out before the maintenance began found that the world effectively collapsed in on itself and lost consciousness. When they woke, they found themselves stuck in a location called "File Island"—a part of a parallel reality, also dubbed "The Digital World" by its inhabitants, called "Digital Monsters" or more often "Digimon" for short. These humans also awoke with a Digivice, a D-Terminal, and a necklace called a Tag that may or may not contain one of nine Crests. Digimon are sometimes inexplicably drawn to these people, and many find out after the fact that their Digivice can be used a catalyst for evolution. Though those trapped in the Digital World are currently unaware of it, their physical bodies are still in reality and currently comatose.
Since this, more Labyrinth Events have been occurring around the world, with no particular rhyme or reason as to when and where they occur. While they were sparse at first, they seem to be increasing in frequency—and more importantly, humans that are present in the radius of one sometimes disappear without a trace, pulled wholesale into File Island without leaving an unconscious body behind when the event ends. They end up in the same situation as those who were trapped in the game, save their later arrival. Even Digimon that are sometimes present for Labyrinth Events ends up with a Tag and D-Terminal when they arrive back home.
At the top of Infinity Mountain on File Island lies a recently-constructed palace. A Hackmon with a Crest of Light, present during the first Labyrinth Event, believes that the Digital World is actually an illusory reality, and the "real world" is the one that humans came from. Now, she seeks to create a permanent bridge to cross into the real world, promising any human who comes to her aid a way home and salvation to any Digimon who help.