One day of DATA1, a virus with artificial intelligence in real-world computers spread, and the virus breeds on the Internet and becomes a creature that evolves into DigitalMonster (commonly known as DIGIMON). The Digi-Core, which controls everything in Digimon, is a program and data (a collection of numbers or symbols of 0 and 1) that are living beings. The forms of monsters and cybrans that can be seen in the eyes of humans are all determined by the information contained in the Digicore.

DATA2 Evolved Digimon are born from Digimon eggs, and the process by which they absorb data or absorb the opponent's data in battle, and change form to a certain extent is called Digimon "evolution". Finally, after the end of life, it turns into a digital egg again. Digimon's evolution is hierarchical, with "Juvenile", "Growth", "Mature", "Complete", and "Ultimate Form", with the highest being of course the Ultimate Form. The powerful Ultimate Digimon has powerful weapons in the real world!

DATA3 Digital World (DW) The world in which the Digimon lives is called DigitalWorld, and it is directly managed by the mysterious host Yggdrasil. On the other hand, Digimon is a living form created by Yggdrasil's experiments in the Digital World! The data volume of the Digimon greatly exceeds Yggdrasil's expectations, and the digital world is facing the expansion of the gigantic universe, and the crisis of the digital world is imminent! If this continues, the digital world will surely collapse!

Digimon's characteristic "evolution" is to increase data in one go, causing it to change its form. In addition, the network interconnects data from outside the digital world and allows Digimon to evolve irregularly. As a result, the availability of the digital world has dropped dramatically!

The project, known as "Project Ark", was carried out to remove all the overloaded Digimon and upload the necessary "Royal Knights" and some research subjects to the new Digital World...... PS: Except for the Digimon of the City of Angels and the Royal Knights who are selected, the rest of the Digimon will be deleted due to the Ark Project