Digimon Adventure 02 is a direct sequel to Digimon Adventure, it takes place three years later. With nearly all of the original characters in high school now, the digital world is supposedly peaceful. Little do they know that a new threat is threatening the digital world he comes in the form of the Digimon Emperor (Digimon Kaiser.) This new villian is human just like the new digidestined. The digimon emperor is enslaving digimon with dark rings and control spires, the control spires make regular digivolving impossible. Three new children are chosen to save the Digital World along with TK and Kairi make up the new digidestined team.

They are given a new digivice called D3, these allow them to transport to the digital world through any computer. Another advantage to the new digivices is that they are able to armor digivolve using a device called a digi-egg, this digi-egg is unrelated to the original digi-egg that digimon are hatched from. Their digimon can armor digivolve in the prescence of the control towers. They eventually stop the digimon emperor who is Ken Ichijouji only after wormon ken's partner digimon sacrifices himself.

After Ken is defeated he joins the digidestined to repent for his wrong doings, they fight two new evil digimon called  Arukenimon and Mummymon. Arukenimon has a unique power to turn the control spires into really strong artificial digimon that are under her control. To fight this new threat the digidestined learn to DNA Digivolve. This enables their digimon to fuse to each other in pairs for more power. Eventually the battle is brought to the real world, we find out that the real enemy is Yukio Oikawa. This man extracts the dark spore from inside ken and places it into other children who wish to be like the old ken (geniuses.) These spores become flowers that harvest the infected childrens energy. 

Eventually the Digidestined confront Yukio Oikawa, they learn he was a extreme loner whose only friend was Hiroki Hida, Cody's father. Hiroki and Oikawa used to play old video games when they were younger eventually becoming obsessed with the digital world and dream of going there one day, but Hiroki dies before they could go together, this causes Oikawa great sadness. In the end a being springs from Oikawas body, Myotismon the real mastermind behind everything from the first adventure now reborn as MaloMyotismon.

The season ends with the help of Digidestineds from around the world, they use the light that exists inside each of them and their wishes to return the Digital World    to a peaceful world again. Oikawa is too weak to enter the Digital world becomes it's guardian as he passes away. After peace is restored, the boundary between the real world and the digital world is broken down, giving every human their own Digimon companion.