While at camp, Tai, Matt, Sora, Izzy, Mimi, Joe, and T.K. come across seven Digivices and are transported to a strange Digital World where they make friends with creatures called Digimon who claim to be their chosen partners.

The kids come across a beach with numerous phone booths, but none of them seem to work.

The kids run away from a Monochromon battle. They come across a trolley car on a small island and decide to spend the night in it, until they are attacked by a Seadramon.

The kids come to a Yokomon village to rest for the evening until a Meramon attacks.

The kids stumble upon a factory where they find an Andromon in trouble.

While escaping the Numemon who attacked the group in the sewers on their way out of the factory, the kids are split up and Mimi ends up in Toy Town.

Tai and Matt argue whether they should climb Infinity Mountain. Joe and Gomamon decide to climb the mountain by themselves. While on the mountain, they are attacked by a Unimon.

The kids meet the ruler of File Island, Devimon, the controller of the Black Gears.

Tai and Agumon land on a snow-covered island and are forced to defeat a Frigimon.

Mimi and Palmon escape Sukamon and Chuumon and cross over to the next island where Izzy and Tentomon landed, but end up getting lost in a labyrinth and attacked by Centarumon.

After an encounter with Ogremon at sea, Joe and Gomamon find themselves on an island with Sora and Biyomon before they are captured by a cult of ghost-based Digimon named Bakemon intent on eating them.

T.K. and Patamon arrive in Primary Village, the place where all Digimon are born. When the baby Digimon start to cry, T.K. and Patamon are confronted by Primary Village's caretaker, Elecmon, which they settle with a tug-of-war match.

T.K. is attacked in Primary Village by Leomon and Ogremon, until Tai, Matt, Izzy, Mimi, and their Digimon arrive to his rescue, where they use their Digivices to free Leomon from the Black Gears. Leomon later explains the legend of the "DigiDestined", a group of children from another world who will save the Digital World from evil forces.

Gennai urges the group to travel to Server to defeat another enemy. Gennai also tells about Crests that will allow Digimon to digivolve further. The kids build a raft and leave File Island and are taken by Whamon to where the Crests are hidden.

The kids arrive in a Koromon village where they are confronted by Etemon. He uses his Dark Network to prevent the Digimon from digivolving and then traps the group inside a cave where they discover their first Crest, Tai's Crest of Courage.

While traveling in the desert the group is trapped by Etemon in a coliseum.

After getting lost in the desert, the group is taken aboard a ship traveling in the desert, headed by Kokatorimon. Kokatorimon captures all the boys and petrifies their partners. Biyomon and Palmon Digivolve and defeat him, and his ship crashes into a giant cactus. Mimi finds the Crest of Sincerity on top of the cactus.

When the group is attacked, Tai and Agumon are hesitant to fight since Digivolving into SkullGreymon. Piximon rescues and trains the DigiDestined at his facility, where Tai and Agumon are stranded in a cave as the others do manual labor. At night, Matt and Izzy sneak away to find the Crest of Friendship and the Crest of Knowledge. However, they are detected by the Dark Network as Etemon sends a Tyrannomon after them. Tai and Agumon regain the courage to fight, leaving to Agumon Digivolve into Greymon and defeating Tyrannomon.

After Izzy receives an e-mail from Datamon, who asks them to rescue him from Etemon's pyramid in exchange for Sora's Crest, T.K. finds the Crest of Hope. Tai, Sora, Izzy, and Joe infiltrate the pyramid, with Tai being overconfident that the Digital World is a virtual reality. However, once Datamon is freed, he kidnaps Sora and Biyomon. Tai becomes too frightened to pursue Datamon after Izzy warns him that they could die.

While the rest of the DigiDestined distract Etemon's forces, Tai and Izzy infiltrate the pyramid to save Sora, where Datamon plans on cloning her to use her Crest and Biyomon to enact revenge on Etemon. Tai musters his courage and saves Sora while Datamon activates the Dark Network to absorb data, including Etemon. Etemon, fused with the Dark Network, fights the DigiDestined, but Tai's Crest allows Greymon to Digivolve into MetalGreymon. When Etemon is defeated, a portal swallows him while Tai and Koromon are sent to Tokyo.

Tai and Koromon arrive home, where they meet Tai's younger sister, Kari, and also learn that not much time has passed since they were in the Digital World. Later, Tai gets a message from Izzy telling him not to return, and he discovers that Digimon are appearing in the Real World. He concludes that they must return to the Digital World and help their friends. After Koromon Digivolves to Agumon to battle an Ogremon, a portal opens and transports both of them back to the Digital World.

Tai and Agumon return to the Digital World to find Tokomon, who reveals that everyone has split up to find them after weeks since their disappearance. Meanwhile, DemiDevimon causes a rift between T.K. and Tokomon and secretly plans on feeding T.K. amnesic mushrooms. Agumon exposes DemiDevimon, and Tokomon Digivolves into Patamon to drive DemiDevimon away.

Matt, Gabumon, Joe, and Gomamon are forced to work at Digitamamon's diner to pay off a meal.

Izzy is trapped in Vademon's pocket dimension and robbed of his curiosity. DemiDevimon attempts to buy Izzy's Crest from Vademon and, in the confusion, Izzy recovers his Crest and his curiosity.

Joe and Tai find Mimi being treated like a princess at a palace. Sora convinces her to sing and awaken ShogunGekomom, but ShogunGekomom attacks the kids.