Off-duty Japan Self-Defense Forces (JSDF) officer and otaku, Youji Itami, is on his way to attend a doujin convention in Ginza, Tokyo when a mysterious portal in the shape of a large gate suddenly appears. From this gate, supernatural creatures and warriors clad in medieval armor emerge, charging through the city, killing and destroying everything in their path. With swift actions, Youji saves as many lives as he can while the rest of the JSDF direct their efforts towards stopping the invasion. Three months after the attack, Youji has been tasked with leading a special recon team, as part of a JSDF task force, that will be sent to the world beyond the gate—now being referred to as the "Special Region." They must travel into this unknown world in order to learn more about what they are dealing with and attempt to befriend the locals in hopes of creating peaceful ties with the ruling empire. But if they fail, they face the consequence of participating in a devastating war that will engulf both sides of the gate. [Written by MAL Rewrite]

This movie takes place after the Adventure series ends. It begins when a new Digimon Egg is found on the internet, and manages to penetrate into almost every computer system in Japan. When the egg hatches, it's identified as a new kind of Digimon, a Virus-type. It sustains itself by eating data from various system, and starts wreaking havok in Japan. As it consumes more and more data, it continues to evolve. And Taichi and Koushiro decide it's time to stop it.

They're off, sending Agumon and Tentomon through the internet to fight off this new enemy. But, with the Virus controlling systems like the American military, all too soon, this digital menace may become all too real. Calling in the help of Yamato and Takeru, they hope that they can stop what's already begun, and maybe save this world a second time.

(Source: AniDB)

Despite the recent Akuma attack, the members of the Black Order are in high spirits as they set about moving to a new base. Immediately upon his arrival, however, Allen Walker is suddenly called by the Central Agency and has his arm forcefully sealed by the Order. He is then led to a surprising meeting with his master, General Cross Marian, who reveals staggering secrets surrounding the enigmatic 14th Noah. A phantom thief incident, the arrival of a mysterious group of Exorcists, the death of an important comrade, and an all-out battle against the Noah Family—just what does this mean for Allen, Yuu Kanda, and the rest of the Order? This is but the beginning of a series of strange, seemingly unconnected events that lead to something far greater. [Written by MAL Rewrite]

The Yamadas and Chi move to a new apartment house, where keeping a pet is allowed.