Five years after the events of Digimon Adventure: tri., Tai and the other DigiDestined are approaching adulthood; however, Tai and Matt still remain undecided about their future goals. The DigiDestined later meet Menoa Bellucci, a professor from the United States, and Kyotaro Imura, her bodyguard. Menoa claims that Eosmon is targeting DigiDestined around the world by robbing both them and their Digimon partners of their consciousness. With Menoa’s help, Tai, Matt, Izzy, T.K., and their Digimon fight Eosmon on the Internet.
When Tai and Matt fuse their Digimon into Omnimon, Omnimon’s form falls apart, allowing Eosmon to escape. In the real world, Tai and Matt find countdown rings on their Digivices. Menoa explains the Digivices are powered by the infinite potential of children, and because Tai and Matt are growing up with their potential fulfilled, they have a time limit before they are separated from their Digimon forever. She also warns them that Digivolving will accelerate the countdown. While Izzy examines Eosmon’s gems, Matt suspects Imura is involved with Eosmon and asks Davis, Yolei, Cody, and Ken to perform a background check in New York. Meanwhile, Gennai visits Tai and Agumon, corroborating Menoa’s statement.
After Eosmon leaves Mimi unconscious, Matt gives Tai and Izzy prepaid mobile phones out of suspicion they are being tracked and also shows them a news article revealing that Menoa used to have a Digimon partner. As Matt continues to investigate Imura, he learns from Davis’ group that Imura’s identity is fake and Eosmon’s data was found on his hard drive, concluding that he is the culprit. Izzy is sent a link to a live stream video of T.K. and Kari held hostage, prompting Tai and Matt to rescue them, while Joe goes missing. By the time they arrive, T.K. and Kari are already unconscious from Eosmon. On the way, Matt confronts Imura, who reveals he is an FBI agent investigating Menoa, and he realizes that Menoa orchestrated the kidnappings and Eosmon as a distraction to target Izzy for the list of DigiDestined. Realizing this as well, Izzy texts Tai with the coordinates to Menoa’s location in the Digital World before she renders him unconscious.
In the Digital World, Menoa confirms that she lost her Digimon partner, Morphomon, prematurely from growing up, and discovered Eosmon’s digi-egg during the recent aurora. To prevent the other DigiDestined from experiencing loss, she has captured their consciousness to allow them to be with their Digimon partners as children forever. Menoa sends a swarm of Eosmon clones to the real world to kidnap more DigiDestined, sparking battles worldwide. Tai, Matt, and their Digimon resolve to stop Menoa even if it quickens their separation, and Agumon and Gabumon DNA Digivolve into Omnimon to fight her and the Eosmon clones. After Menoa biomerges with Eosmon, Eosmon cuts Omnimon into pieces, causing it to split again. Tai and Matt are assaulted by the DigiDestined and their Digimon partners, but Tai grabs Kari’s whistle and blows into it, awakening and turning them back to normal. While the DigiDestined and their Digimon partners join the battle, Tai, Matt, and their Digimon make one final Digivolution, forming Agumon (Bond of Courage) and Gabumon (Bond of Friendship). The two Digimon defeat Eosmon, with Menoa finding closure with Morphomon.
After the battle, Imura arrests Menoa. Tai and Matt spend their remaining time with Agumon and Gabumon respectively until they vanish and their Digivices turn into stone. In the following spring, the two move on with their lives and pursue their dream careers, under the belief that they may see their Digimon partners again in the future.