A spirit named Kopu visits Kentaro and Takeshi, two boys born at the exact same time, and reveals their secret destiny: to save the world from Gomon, an evil spirit, by transforming into a powerful defender.

Pacifist Kentaro gives the radar to Takeshi for him to take care of threats on his own, but when Gomon attacks Kentaro's father after possessing a car, Kentaro realizes he cannot remain on the sidelines.

Kentaro and Takeshi attempt to evacuate a zoo holding a concert for its 100th anniversary before Gomon, inhabiting one of the zoo's monkeys, wreaks havoc on the attendees.

During a visit to a biotechnology lab, Kentaro and Takeshi form Barom One to fight a giant, carnivorous plant retaliating against a gang of cruel children who abused its brethren.

A burglar steals a swarm of highly valued beetles but gets more than he expected when Gomon possesses the insects and they attack him, forcing Barom One to rescue the thief.

Kentaro's mother studies the monster's DNA for a better understanding of the threat Earth faces; Kenichi finds a clue in the pattern of energy throughout the city.