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 Bakemon intent on eating them. Gomamon and Biyomon manage to escape and Digivolve to fight Lord Bakemon. Joe uses a Buddhist mantra to weaken Lord Bakemon. After Birdramon and Ikkakumon destroy Lord Bakemon, they ride across the sea to find their friends.

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-o-war match. Patamon wins and earns Elecmon's respect and trust, as he allows the both of them to stay. Meanwhile, Devimon sends Leomon after T.K, considering him a threat.

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 prophecy that the children, as "DigiDestined", are to the saviors of the Digital World. The group fights Devimon, who absorbs Black Gears and Ogremon. Devimon defeats the DigiDestined, even when Joe and Sora rejoin them. Patamon Digivolves into Angemon when T.K. is in danger and sacrifices himself to defeat Devimon. Angemon's data reconstitutes into a DigiEgg, and File Island begins to reform itself. The DigiDestined are then suddenly contacted by Gennai.

Gennai urges the group to travel to Server in order to defeat another enemy, informing them about Crests, which will allow their Digimon to Digivolve even further. While traveling on the ocean, the DigiDestined are swallowed up by Whamon, who is under the control of a Black Gear. Tai frees him with his Digivice, and as gratitude, Whamon takes the DigiDestined into an undersea store where the Crest tags are located. They fall under attack to Drimogimon and free him from a Black Gear. After recovering the tags, Whamon proceeds to take them to Server.

On Server, the DigiDestined arrive at a Koromon village, only to find Pagumon living there. Despite the Pagumon's warm welcome, they are allied with Etemon and abduct Tokomon at night, imprisoning him with the Koromon. The DigiDestined rescue them, but Etemon uses his Dark Network to defeat them and destroy the village. The group take refuge in a cave, where Tai finds the Crest of Courage, allowing them to escape from Etemon into the desert.

Joe's tag leads the DigiDestined to a coliseum, where Etemon traps them and forces Greymon to fight another Greymon. After Joe finds the Crest of Reliability, the group escapes and Tai forces Greymon to Digivolve to his ultimate form by putting himself in harm's way. Instead, Greymon Dark Digivolves into SkullGreymon, attacking everyone before eventually reverting to a regretful Koromon.

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.

After T.K. finds the Crest of Hope, Izzy receives an e-mail from Datamon, who asks them to rescue him from Etemon's pyramid in exchange for Sora's Crest. 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 finds Joe working at Digitamamon's diner to pay off his debt and agrees to help. DemiDevimon bribes Digitamamon to keep them while setting off accidents that makes Matt question Joe. However, once Digitamamon's scheme is exposed, they battle him with Tai and T.K. Joe sacrifices himself to save T.K., leading Matt to see him as a true friend and allowing Garurumon to Digivolve into WereGarurumon. After Digitamamon's defeat, the group splits up and continue their search for the remaining DigiDestined.

Izzy falls into Vademon's pocket dimension and is forced to give up his curiosity. Tentomon snaps Izzy out of his trance, but by that time, DemiDevimon tries to buy Izzy's Crest from Vademon. In the confusion, Izzy recovers his Crest and his curiosity as he causes Kabuterimon to Digivolve into MegaKabuterimon, defeating Vademon. Izzy and Motimon are found by Matt and T.K. soon after.

Tai and Joe find Mimi with the Gekomon and Otamamon, who treat her like a princess hoping that her singing voice will awaken ShogunGekomon. However, Mimi becomes too consumed in being pampered to give it up and imprisons Tai and the others after they attempt to record her voice. After a nightmare, Mimi apologizes and awakens ShogunGekomon. ShogunGekomon, however, attacks Mimi, causing MetalGreymon to defeat him.

The DigiDestined find Sora, realizing that she had been helping them in secret. Sora is convinced by DemiDevimon that her Crest would never glow, recalling her relationship with her mother. At night, Myotismon appears, defeating the Digimon. Sora tries to stop an injured Biyomon from fighting for her well-being and realizes that her mother's actions towards her were the same. Birdramon is able to Digivolve into Garudamon, and the DigiDestined escape.

Gennai appears and tells them that there is an eighth DigiDestined and that Myotismon is planning to go to the Real World with an army of evil Digimon to find the child. The DigiDestined infiltrate Myotismon's castle to stop him entering the Real World, but they fail when Gatomon distracts them with Devidramon.

The DigiDestined travels to Gennai's home, where he unravels secrets about the Digital World. They return to Myotismon's castle to open the gate and battle Dokugumon. The fight causes the castle to crumble as WereGarurumon destroys Dokugumon, but they manage to open the gateway and escape through it.

The DigiDestined find themselves back at camp, learning they were only gone for a few minutes. They proceed to head towards Highton View Terrace to try to find the eighth child. There, a battle between Garudamon and Mammothmon helps them recall them witnessing a battle four years ago between a Greymon and a Parrotmon. They surmise that the eighth child must have also seen the fight.

The DigiDestined try to get back to their homes in Odaiba after missing their train stop and spending all their money on food. Eventually they end up getting a ride from Sora's cousin Duane,[10][Note 3] who later accidentally pushes Izzy off a bridge. After Ikkakumon defeats Gesomon at the ocean, he carries the DigiDestined home.

After the DigiDestined return home, the eighth child's Digivice gets carried off by Tai's cat and sets off a signal that brings in DemiDevimon, Raremon and Izzy. Kabuterimon manages to defeat Raremon, but Izzy and Tentomon's search leads them to no results.

While DigiDestined continue their search for the eighth child, Sora and Mimi head to Tokyo Tower and encounter SkullMeramon, battling him. Tai and Izzy come to their aid, with Greymon Digivolving to MetalGreymon and defeating him while Kabuterimon saves the Tower. Meanwhile, Gatomon meets Kari and realizes that she is unable to kill her.

T.K. and Patamon get into a fight on their way home, and when Patamon flies off, Matt and T.K. follow him into Shibuya. They encounter Pumpkinmon and Gotsumon, who are more interested in having fun rather than helping Myotismon. When they refuse to fight Matt and T.K., Myotismon punishes them.[Note 4] Angered, WereGarurumon and Angemon drive Myotismon away.

With Wizardmon's help, Gatomon discovers that Kari is the eighth child and she is her partner. Entrusting Kari's Digivice to Tai, Wizardmon and Gatomon infiltrate Myotismon's lair to steal the Crest of Light. Myotismon catches them in the process and discovers the truth as well, throwing Wizardmon into the ocean while holding Gatomon captive.

Myotismon surrounds Odaiba in fog and has his followers capture all families living in the city. Among the prisoners, Sora and Mimi try to plan an escape, using Joe's Buddhist mantra to weaken the Bakemon. However, Phantomon is unaffected and DarkTyrannomon overpowers Togemon. After Togemon Digivolves into Lillymon to tame DarkTyrannomon, she finds herself facing Myotismon while Biyomon Digivolves into Birdramon to drive off Phantomon.

Sora escapes, but Mimi is recaptured, while Izzy heads to Fuji TV Station. Joe and T.K. travel back through Odaiba Bay and find Wizardmon, but they are attacked by MegaSeadramon, who is defeated by Ikkakumon's ultimate form, Zudomon. Tai entrusts Kari to Matt before heading towards the convention center, but Phantomon follows Sora to them. Kari sacrifices and reveals herself as the eighth child in exchange for their safety.

The DigiDestined reunite at Fuji TV Station to fight Myotismon and Phantomon. Myotismon tries to kill Kari and Gatomon, Wizardmon sacrifices himself to protect them. Distraught, Kari causes Gatomon to Digivolve into Angewomon, destroying Myotismon with a combined attack. However, fog still remains around Odaiba.

Myotismon is reborn as VenomMyotismon, empowering himself by consuming his army before advancing to the convention center for the humans. Recalling Gennai's prophecy from earlier, Izzy discovers that Angemon and Angewomon must strike Tai and Matt in order to bring about a miracle that will allow them to defeat VenomMyotismon. Tai and Matt risk their lives and fulfill the prophecy, allowing Agumon and Gabumon to Warp Digivolve into WarGreymon and MetalGarurumon.

VenomMyotismon is defeated after he exposes his weak point, which WarGreymon and MetalGarurumon exploit. The fog clears to reveal the Digital World reflected in the sky, and the DigiDestined realize that the boundaries between both worlds have begun to intersect, as years have passed in the Digital World since their departure. The DigiDestined decide to return to the Digital World, leaving their families.

As the DigiDestined return to the Digital World, they encounter Chuumon, who tells them that the Dark Masters have taken over the Digital World while they were in Tokyo. The DigiDestined face the Dark Masters, who overpower their Digimon, and Chuumon sacrifices himself to protect Mimi. Pixiemon arrives to save the DigiDestined, sacrificing himself to allow them to escape.

The kids manage to escape MetalSeadramon's minion, Scorpiomon. They attempt to escape by sea, but they are immediately stopped by MetalSeadramon.

Under attack from MetalSeadramon, Whamon comes to the DigiDestined's rescue and they flee to the bottom of the ocean. Unfortunately, MetalSeadramon and his army of Divermon find them. Whamon and Zudomon destroy the Divermon, while WarGreymon battles MetalSeadramon.

Whamon sacrifices himself while saving WarGreymon, allowing WarGreymon to defeat MetalSeadramon. The DigiDestined proceed to Puppetmon's forest, where he separates them, causing Matt to become overprotective of T.K. Puppetmon forces T.K. to play deadly game of hide-and-seek in exchange for the DigiDestined's safety, but T.K. tricks him and sabotages his control room. After the other DigiDestined regroup and defeat Kiwimon, Matt becomes discouraged seeing that T.K. has escaped without his help.

While Puppetmon orders Garbagemon to attack the DigiDestined, Matt withdraws and meets Cherrymon. Cherrymon convinces him to defeat Tai, who he claims is the source of Matt's self-doubt. Matt returns to the DigiDestined and demands Tai to fight him, while Cherrymon is killed by Puppetmon after warning him not to underestimate an advantage that the DigiDestined have over him.

Tension runs high as a fight breaks out between Matt, Tai, and their Digimon. Kari's body is taken over a strange entity, who explains why the DigiDestined were chosen to save the Digital World. Uncertain, Matt leaves the group. Upset from the conflict, Mimi leaves as well, with Joe accompanying her. The rest of the DigiDestined continue their journey to fight the Dark Masters.

Joe and Mimi rescue an injured Ogremon, while Etemon returns as MetalEtemon to take revenge on them. Meanwhile, Tai's group infiltrate Puppetmon's mansion with the help of two of his playmates, keeping Puppetmon at bay with his own cannon.

SaberLemon rescues Joe and Mimi, but they are found by MetalEtemon again. He destroys MetalEtemon with Joe and Zudomon's help but dies from a fatal wound from protecting Mimi. At the same time, Puppetmon is defeated by the DigiDestined and destroyed by Matt and MetalGarurumon upon escaping. Recognizing Puppetmon's defeat and Leomon's sacrifice, Mimi regains her will to fight as she and Joe decide to gather more reinforcements while Tai's group fights the remaining Dark Masters.

Kari falls ill, and Tai becomes nearly hysterical as he and Izzy search for medicine. However, the DigiDestined learn too late that the city they are in is under Machinedramon's control. Although they dismantle the tracking system, Tai and Izzy return and are nearly killed by a Megadramon and Gigadramon, but Angemon saves them. Unfortunately Machinedramon fires at the building the kids are in, sending them into the sewers below.

Kari recovers, and, along with Sora and T.K., begins searching for the others. Encountering WaruMonzaemon, Kari frees the Numemon he has enslaved and her Crest re-energizes the Digimon. Tai and Izzy are found by Andromon, and once they are reunited, they battle Machinedramon. After Numemon sacrifice themselves to save Kari, WarGreymon destroys Machinedramon.

As Joe goes off on his own to find Matt, Tai's group encounters LadyDevimon, one of Piedmon's servants. Sora and T.K. are sent to locate the rest of the missing DigiDestined while Angewomon and MegaKabuterimon face and defeat LadyDevimon. After LadyDevimon's defeat, Piedmon approaches the group.

Piedmon and WarGreymon battle, but WarGreymon cannot stop him alone. Matt falls into a dark cave, but he escapes once he confronts his feelings. After rescuing Sora from her dark cave, they return with Joe. Matt makes up with Tai, activating the Crest of Friendship. With all of the DigiDestined but Mimi reunited, both WarGreymon and MetalGarurumon prepare to battle Piedmon.

Piedmon turns the DigiDestined and their Digimon into doll keychains. With T.K. and Kari remaining, T.K. imagines Matt giving him advice, regaining hope and activating his Crest. Angemon Digivolves into MagnaAngemon and saves the rest of the DigiDestined, and together, they defeat Piedmon when Mimi reunites with the group. The DigiDestined are unable to celebrate their victory when they receive an e-mail from Gennai, who reveals that another enemy is the true cause for the destruction of the Digital World.

Although the Dark Masters are defeated, it is not enough to stop the complete destruction of the Digital World and the children and their Digimon are forced to face the true mastermind of all the chaos - Apocalymon.

Apocalymon is defeated, and the DigiDestined prepare to spend the rest of their summer in the Digital World. However, Gennai informs them that they either have to leave quickly, or remain in the Digital World forever.