Digimon Tamers: Battle of Adventurers (2001) Anime Watch

Takato and Guilmon go on vacation to Okinawa and meet a fellow tamer, Minami. Back in Japan, a popular computer pet suddenly becomes a virus, infecting all of the computers who have it. As the virus spreads, Takato tries to figure out why digimon are all attacking his new friend, and what her connection is to the virus.