Takato Matsuda, Ruki Matsuno, and Lee Jenrya are children who have, by fate, recieved real Digimon, unlike the imaginary ones in the card game they play. Each of the children, or "Digimon Tamers", have their different views on how Digimon should be treated. But when other Digimon begin to appear around Japan, they must put aside their differences to fend off the digital intruders; even though Yamaki, who is the head of a secret organization called Hypnos is trying to eliminate all of the Digimon himself.
Squid Girl has come to the land from the depths of the sea to conquer humanity for its pollution of the ocean. Unfortunately she ruins the first house she uses as an invasion base and has to work to pay for repairs. Of course, she can't overcome the Aizawa sisters who manage the house, so who knows whether she can subjugate humankind.