In season 1 of digimon, 7 kids go to the same summer camp and see a strange opening in the sky. It is also snowwing despite being summer. 7 orbs of light descend down as well. They are 7 digivices; one for each child. After questioning what they are, the kids are transported to a strange world where they find 7 small digimon: Koromon, Tsunomon, Yokomon, Motimon, Tanemon, Bukamon, and Tokomon. During a fight with Kuwagamon, all the digimon digivolve to Rookie level. The kids are still complaining and are trying to find a way home. Each of the kids, except for T.K., make their digimon digivolve to Champion to help the digimon that are under the control of Black Gears. The kids, now known as digidestined, find out that they came to the Digital World and Devimon is the one controlling these digimon. During the fight with him, Patamon digivolves to Angemon and uses all him power to defeat him.

After the dramatic fight with Devimon, the digidestined are contacted by an old man named Gennai. They must go to the continent of Server to find their Tags and Crests. With them, their digimon will be able to digivolve a step higher, to ultimate level. The digidestined first made a raft but later traveled across the seas in a Whamon. On Server, they find an ultiamte level enemy named Etemon. He has all this information and locations across Server due to his Dark Network. The digidestined all find their crests. During the battle with Etemon, Tai makes Greymon digivolve to MetalGreymon and destroy Etemon. After winning, Tai and the de-digivolved Koromon are transported back to Earth.

After returning to the digital world, Tai discovers that the group is split up after looking for him. There is also a new enemy, Myotismon. All the digidestined, except for Mimi, Joe, and T.K., make their digimon digivolve into ultimate during this time. Gennai reveals that thier is one more digidestined. The 8th digidestined is on Earth and the digidestined have to find him/her first before Myotismon does. If Myotismon finds him/her, he will kill the child and his/her partner digimon. The digidestined use Myotismon's gate to retun home. Myotismon has sent his servant digimon, one of which being Gatomon, around to look for the child using copies of the child's crest. Myotismon has the original. He doesn't have the digivice though. While in the real world, Mimi and Joe make their digimon digivolve into Ultimate. Wizardmon, a digimon that works for Myotismon only because he is Gatomon's friend, finds the Digivice. Instead of giving it to Myotismon, he gives it to Gatomon. He reminds her of something Gatomon said a long time ago. She said "I just keep waiting for her.", but she didn't know who she was waiting for. She realizes that she is the 8th digidestined's digimon and that Kari, Tai's sister, is her partner. Gatomon talks to Kari and everyone decides to hide this information so Myotismon doesn't find out. Eventually, Myotismon does during the fight against him. He tries to kill Kari and Gatomon but Wizardmon sacrifices himself to save them. In the process, he is killed. Gatomon digivolves to Angewomon and destroys Myotismon. However, the fog created by him doesn't go away. He returns as VenomMyotismon, a mega-level digimon. Until that time, Mega level digimon were not known to the digidestined. After being shot with the arrows of Hope and Light, Tai and Matt are able to make their digimon warp-digivolve into mega-level. After defeating VenomMyotismon, the digidestined notice that the Digital world is visable in the sky. They decide to return.

While they were in the real world, years have gone by in the Digital world. The Digital world was taken over by The Dark Masters, four mega-level digimon. All the digital world was now on Spiral Mountain. MetalSeadramon had taken over the water portion, Puppetmon had taken over the forest, Machinedramon had taken over the city, and Piedmon was at the top of the mountain. Metalseadramon was defeated by WarGreymon first. Puppetmon was the next Dark Master that the digidestined faced. He was defeated by MetalGarurumon. The children had split up again by that time. Etemon had retuned as MetalEtemon but was defeated by Zudomon and Saberleomon. Machinedramon was defeated by WarGreymon. There was one Dark Master left. Piedmon, the strongest of the Dark Masters remained at the mountain's peak waiting. WarGreymon fought to hold him off until everyone else got there. Matt, Joe, Sora, and T.K. arrived with their digimon. MetalGarurumon healed WarGreymon and they fought Piedmon. However, they were all tune into key chains except for Kari, T.K., and Angemon. Angemon digivolved into MagnaAngemon and sealed Piedmon in him Gate of Destiny. He then retuned everyone to normal. Mimi arrive right after this.

Gennai informed the digidestined that the Dark Masters weren't the only problem. Apocalymon, the creator of The Dark Masters, had to be defeated. At the beginning of the fight, he de-digivolved all their digimon to Rookie level. He also broke their Crests and Tags. The children used the crests' power within themselves to digivolve their digimon. The digidestined contained him uses their digivices. The digidestined were told that now they had to return to the real world and leave thier digimon behind. After sad goodbyes, the digidestined left for Earth. They were reunited with the digimon later, don't worry. :)