Takato thinks that after all the struggles he and Guilmon should take some days off and therefore they travels with Calumon to the island of Okinawa, where they want to visit his cousin Kai living there with his grandfather. Together they are swimming in the depths of the beautiful ocean and discover a lot of exotic animals. But they also meet a girl chased by a Digimon. Guilmon and Takato plunge immediately into the battle and save the girl whose name is Minami Uehara. She is the daughter of the inventor of the original V-Pets, Takehito, and he gave her his laptop, so that data are safe. And this exclusive data stored on this laptop are the reason why the girl was pursued. Minami tells Takato and Kai that the first V-Pet is desinged in memory of her dead dog, Mei but it was only a small consolation since Minami gives herself the blame for the death of her best friend.

Again Digimon appear and attempt to steal the data. While Takato and Guilmon protect Minami bravely a new and unknown Digimon jumps out of the laptop. It is Shisamon and seems to have good intentions, because it also attempts to protect Minami. But it is no big help 'cause Minami is attacked by one of the Digimon and dragged into the center, where her father is working and where he once developed the V-Pet. Takato, Guilmon, Kai and Seasarmon make their way immediately to this place to save her and they are able to sneak in the building after several small fights. Takato and the Digimon can free Minami and her father but as they wanted to escape the group is suddenly stopped by someone who don't wanna let them go. A man disguised as a Digimon. Mephistomon, an Ultimate Level Digimon planning to destroy the world caused by his hatred of the whole life. It looks like the President of VP Laboratories and so it was ablte to install a computer virus on the V-Pet's which are already on the market in order to make all Digimon obeying him

In the meantime, Henry and Rika also fight against wild Digimon appearing in the city. The reason is that all the V-Pets in the whole world are going crazy and Digimon can come to this world.

Is it possible for the Tamer to take down the evil Digimon and to bring back all the other Digimon again to their own world?