After the events of Digimon Adventure 02, normal life gradually resumes. That peace is disrupted when a familiar icon begins appearing on computer systems throughout Japan. The icon spreads far beyond PCs, showing up on TVs, mobile phones, video games, and any device with an online screen. It seems to be hunting for Yagami Taichi and Ishida Yamato, the two who defeated it years earlier. In reality, the icon is Diablomon, the virus‑type, jellyfish‑like Digimon that was conquered in the second movie. This time, however, Diablomon has learned to manifest physically and is sending thousands of copies into the real world. Koushiro and Ken devise a plan to rid the world of the virus once and for all.