Plot
In 2012, a giant Digi-Egg appears over Tokyo, transmitting a mysterious message that wishes for everyone on Earth to have a Digimon friend. The Adventure 02 DigiDestined encounter Lui Ohwada, who claims to be the first chosen child and attempts to reach the Digi-Egg. While assisting Lui, Davis, Ken, and their Digimon accidentally fall through the Digi-Egg and are transported back to 1996. They witness a younger Lui, who is abused by his mother, discovering a Digi-Egg. Older Lui tries to stop him, but they are then returned to the present.
Lui shares his life story with the DigiDestined. The Digi-Egg he encountered in the past hatched into Ukkomon, a Digimon that could grant wishes, who gave him the very first Digivice. Over the years, Ukkomon gleefully manipulated Lui's parents, friends and neighbors into treating him kindly. However, Lui eventually learned that his wish had led to the increase in number of other DigiDestined who were risking their lives in battles alongside their Digimon partners, much to his horror. Lui confronted Ukkomon, but the Digimon innocently declared that everything had been done for Lui's happiness. Lui accidentally injured his right eye in anger, and Ukkomon gave him his own eye as a replacement. A mentally unstable Lui insulted Ukkomon furiously, causing the Digimon to melt away and disappear, also as a result, Lui's parents suddenly ended up dropping dead due to Ukkomon puppeteering them for too long.
In the present day, the Digi-Egg hatches into a giant Ukkomon, who reappears to give Lui a birthday present, which will force a Digimon on every human on Earth, throwing society into chaos. The DigiDestined plan to stop Ukkomon but become hesitant, after T.K. becomes concerned that defeating him may nullify the relationships with their own Digimon. Davis and Veemon convince them that their relationships developed naturally and were not forced. Lui decides to meet Ukkomon, and with the help of the DigiDestined, reaches the giant Digimon. Lui resolves the issues with his mother and younger self by talking sense into the former, then confronts Ukkomon about their true feelings, and promises to reunite in the future before Lui asks the DigiDestined to destroy Ukkomon. After a short battle, Imperialdramon Fighter Mode destroys the giant Ukkomon, resulting in Ukkomon's reduction to a small Digi-Egg held by Lui who loses the eye that Ukkomon gave him. Digivices around the world start to disappear, showing that the DigiDestined and their Digimon no longer need a medium to connect with each other.
In the post-credits scene, Lui's Digi-Egg starts to hatch.