This is the way the world ends. Not with a bang but a whimper. Milleniummon, the evolved form of Kimeramon, reigned chaos on the Digital World, flattening the world that was left behind and leaving it a wasteland prime for Zony's takeover. However, brave young children rose to defend the world, bestowed with the power of Calumon's gift which allowed them to ascend to a new level of digivolution known as the Biomerge, where humans and Digimon become one. With this, they were able to overcome Milleniummon and save the Digital World. However, exhausted as it was the Digital World soonafter closed its gates, forcing children and digimon to decide if they would remain in the Digital World permanently, or go back to the human world.
A year and a half passed where the human and Digital World were segregated in every way. However, with time between the two worlds out of sync, 1.5 years in the Real World was 5000 years in the Digital World, and things changed. Daemon secured his dominion over the Digital World, seizing control of all except for the Holy Capital, protected by Lord Seraphimon.
The company known as Zony was still in recovery as they noticed yet another problem, the American Digital World they had been dealing with was just one of many servers. A Japanese server had made connection to the Real World and released Digimon into the real world, many of whom found partners with the children of Tokyo. The looming question is why?