The story of D4 is as simple as this...

Many digimon, called The Resistance, believe that they should be free and not governed like in the old days. These digimon believe that they are not humans, they are some form of digital animals and they are not like the real world. Then you have, another group called The Organization, the Pro-Government group of digimon. Digimon of this group constantly argue with The Resistance simply because they feel a little order won't hurt anyone, if things are judged and govern then there will be less problems and things will have balance...and then you have The Indifferent, they don't care eaither way...these digimon try to pull away from the arguing so they don't side or help anyone thats not of their own when it comes to debates.

A virus has hit the digital world, and its not a regular virus that can be destroyed with a simple virus scan and delete. Many people blame Kyoda Ichido, formally known as Zaden. They say that he brought the virus and that is why Digimon bicker over the government system...but really is it?

To get down to the bottom of this, Gennai asked permission from his other 4 Program leaders to bring choosen ones to the digital world, maybe they can stop this virus...seeing as it was caused by a 'human' it may be able to be deleted by one. But its not as easy as it seems? Nope. It never is.