Tomorou Tenma possesses a uniquely strong e-Pulse—the energy created by human thoughts and emotions that powers egg-shaped AI devices named Sapotama. The world's everyday life relies on the assistance of Sapotamas, but the force of Tomorou's e-Pulse often causes glitches in them. One night, a strange creature calling itself Gekkoumon emerges from his device and insists on eating Tomorou's e-Pulse. Gekkoumon is a Digimon, a creature feeding on e-Pulse that was born from an error in Sapotamas. Some Digimon completely drain humans of their energy, leaving them in a comatose state known as Cold Heart. When Tomorou's older brother, Asuka, becomes a victim of this phenomenon, Tomorou vows to avenge him. Tomorou meets a group of Digimon-wielders called Glowing Dawn, who hunt down rogue Digimon for bounties. Their leader, Kyou Sawashiro, explains that there might still be hope for Asuka's recovery. Although Tomorou struggles to trust these strangers, he decides to join them, as he realizes that saving his brother may not be achievable on his own.

A comet burns in the sky, its brilliant light shining down upon the people of Earth. At that time, a giant army of viruses invade the real world, crushing everything in their path. Netto and Enzan use cross fusion to intervene, but are whisked away to an unknown location, only to be confronted by the one responsible for the attack - Duo! (Source: Official Site)

It's a quick time jump to the 26th century where a school trip to a rebuilt 21st century city turns into a wild adventure for teenaged Shinichi. While chasing a talking deer that steals his bag, he runs into a strange girl trying to elude even stranger pursuers, and then things get really wild. It's a mad dash through a city of the past as two young people discover a chance at a new future. (Source: The Anime Network)

A boy gets involved in an accident when in kindergarten, horribly damaging his arm, but the doctors somehow manage to save it. Now, several years later, his arm seems to be becoming the focus of strange events as it turns out to be more than a normal arm. Meanwhile, a secret organization is out to get hold of him and the power he possess.