While preparing for the upcoming school camp, Taichi Yagami is visited by his new neighbor Koshiro Izumi when they learn that Tokyo’s electronic systems have gone haywire, including the city's trains with Taichi's younger sister Hikari and their mother trapped in one. The two youths run to the nearby station where Taichi is suddenly transported to another world located inside the internet, encountering a wounded Digimon called Koromon. Upon making contact with Koromon, Taichi gains a Digivice while Koromon evolves into Agumon. Koshiro, who also obtained his own Digivice, contacts Taichi and informs him that a horde of Digimon called Argomon are responsible for the chaos with Taichi and Agumon battling them to save the former’s family. Though the remaining Argomon evolves into more powerful forms before overpowering them, Taichi and Agumon’s determination triggers the latter’s evolution into Greymon.

Yamato joins Taichi and Koshiro on their mission to stop the Argomon hacking into the U.S. military. On their way there, they learn the Argomon hijacked an American nuclear submarine which is about to launch a nuclear missle. Greymon and Garurumon work together to defeat the Argomon leader who evolves into a perfect form. Yamato then comes with an idea to defeat the leading Argomon which would endanger Greymon and Garurumon, but Taichi convinces him to proceed as their Digimon launch point blank attacks at the Argomon leader. But the Argomon leader survives and evolves into his ultimate form as the missile is launched. Koshiro informs them that the missile is targeting Tokyo, and when Taichi and Yamato refuse to give up, their Digimon partners suddenly merge into Omnimon when Hikari and Yamato’s younger brother Takeru came in contact with some feathers falling from the sky.

The US army's tactical network had been corroded by Digimon, causing military systems to go haywire. Taichi and the others fight desperately against the enemy Digimon in order to put an end to the threat of the missile launch, however the more enemy Digimon they defeat, the more they evolve. And finally, the missiles are launched at Tokyo. Furthermore, bullets of light fired by the enemy Digimon hit Greymon and Garurumon directly. Then, an enormous white Digimon appears... !?

Taichi arrives in a world called the "Digital World" where Digimon live. His classmate Sora appears there, and together with Taichi and Agumon, they begin their journey by heading for a "shrine".

The time frame for Tokyo's urban functions coming to a halt was drawing near. Taichi, Agumon and Sora head for a "shrine" written about on a lithograph of the Digital World in search of clues. Meanwhile, Koshiro, who is at another location in the Digital World, continues to gather information along with Tentomon, the Digimon he met there, while keeping in contact with Taichi. During that time, Koshiro and Tentomon get swallowed by a mysterious huge Digimon...

Taichi’s party comes across an orchard and meets a mysterious girl, Mimi. Taichi and his friends find out that a kingdom is targeted by some ferocious Digimon.

The children now know that the Holy Digimon is the key to saving Tokyo from the blackouts. They attempt to cross the sea to get to the continent, but they’re suddenly attacked by a mysterious whirlpool.

The children finally succeed in crossing the sea with Ikkakumon’s help. However, what awaits them on the other side is a fortress full of Digimon…

The six children and Digimon neutralize the fortress thanks to excellent teamwork. They try to decode the enemy’s communication log and obtain new information about the Holy Digimon. However, it’s not long before new enemies approach the fortress one after another.

The battle between Greymon and Orgemon ended abruptly and now the Chosen Ones discuss their next move. Taichi and Agumon take a chance to defeat the ultimate enemy, so that the others can safely head to their next destination.

The six Chosen Ones who had finally gathered split up again into two teams in order to find the Holy Digimon. As Yamato’s team attempts to cross the desert, they encounter some dust devils.

Taichi’s team reaches an ancient ruin. While Koshiro tries to analyze the characters on the walls, Mimi and Palmon accidentally fall underground. When they’re in danger, they encounter a kindhearted Digimon.

Yamato’s team flies above an endless jungle on Birdramon until they come across a floating fortress. Sora’s caring heart that wants to save Digimon in trouble brings about a new glow on Piyomon.

Taichi’s team reaches a canyon where they are attacked by a swarm of insect Digimon. In the chaos that ensues, Koshiro and Tentomon stand up to protect their friends.

While Taichi’s team finishes fighting off Oukuwamon and Kuwagamon in the canyon maze, Sora’s team reaches a snowy mountain where they are attacked by a group of Digimon. Joe and Ikkakumon stand up to save Sora from danger.

Taichi’s team finds a strange cave that leads to Tokyo. Excited to be back, the children attempt to get home through the subway. However, a creepy Digimon prowls the city, and there, the children learn a shocking truth.

Just when Taichi and his friends thought they had finally defeated the enemy in the fake Tokyo, a new enemy appeared. The children work together with their Digimon to take down the eight-headed Ultimate Digimon.

The Chosen Ones worked together and succeeded in defeating Ultimate Digimon Orochimon. However, a mysterious countdown begins. To save Tokyo, they must prevent it from reaching zero

Thanks to Omegamon’s reappearance, the Mega Digimon Nidhoggmon, was finally defeated. However, Sora and the others disappeared after being swallowed by a storm. Taichi and Yamato, who are left behind in the Digital World sneak into Valvemon.

Yamato’s younger brother, Takeru, is unexpectedly found in the Digital World, held captive by a powerful Digimon. With the help of Leomon’s army, Taichi and Yamato attempt to save Takeru.

The Holy Digimon that turned into a Digitama was snatched away, and Taichi and Yamato chase after Skullknightmon. Meanwhile, the rest of the Chosen Ones that are back in Tokyo fight remotely with their partner Digimon in the Digital World.

Thanks to Takeru’s bravery, Taichi and the others found the way into the castle where the Digitama is held. As for the Chosen Ones in Tokyo, they were in a remote battle against Calamaramon to stop an uncontrollable tanker from crashing.

Devimon’s castle collapsed after the fierce battle with Darkknightmon and Taichi’s group comes to face Devimon at last. Meanwhile, the rest of the Chosen Ones and their partner Digimon fight to destroy the obelisk that is transferring energy.

Thanks to Koshiro’s group destroying the obelisk which was transferring energy to the Digital World, Taichi and the others defeated Neodevimon at last. However, Taichi struggles against the overwhelming powers of Donedevimon

The battle with Donedevimon is over at last. However, destiny wasted no time in bringing the next adventure to the Chosen Ones. Koshiro’s group is dealing with tanker collisions while Taichi’s group is attacked by a cluster of Mamemon.