From the introduction:
It's the early 2000s, computer technology is growing by the day and Digimon is the most popular thing with the kids. They watch the adventures of the digidestined on TV, play the card games before and after school, even collect the toys.
Unbeknownst to all but a few, Digimon aren't just fiction. In the 1980s, a group of programmers from all over the world called the "Monster Makers" joined together and succeeded in creating artificial life, before their funding was pulled.
One member of the group, unwilling to let go, continued independent research on these new lifeforms after the team was disbanded. The man named Shibumi continued working, advancing the these "digital monsters" and the "digital world" they inhabited.
His research was said to have ended in the early 90s after a car crash reduced him to a comatose state, but a mysterious figure still lurks, spreading mysterious "Blue Cards". Human children who come upon these cards become "Tamers" of Digimon.
Working together, they defend the real world from hostile Digimon invading from the other side. Meanwhile, a government agency known as "Hypnos" watches from the shadows, monitoring the activity of Digimon, dubbed "Wild Ones" by the group.
The conflict between humans and Digimon is only beginning, but as they focus on one another, something sinister lurks beneath it all, festering, growing. . .