On summer vacation in Okinawa with his partner Guilmon, Takato Matsuda meets Minami Uehara, a girl whose late dog inspired her father's virtual pet program, the V-Pet. When someone infects the V-Pet with a computer virus tied to the demon Mephistomon, the program starts pulling real Digimon into the world through every device running it. Takato calls in Ruki Makino, Jianliang Li, and their partners to help Minami stop the outbreak before Mephistomon's plan goes further.