A Continuation of the original Dagwon Series. Peace is restored and the original cast return to their normal life. The sudden appearance of a new mysterious boy that appeared and was chase by no other than their own ally from the past demanding the Dagwon crew to turn the boy in. The dead from the past also make an appearance in this OVA. So the new adventure and excitement begin a new.

A huge space monster appeared in a city and began to destroy the city. People were escaping with screaming. Among them, there were five high school students, En, Kai, Shin, Yoku, and Ryu. However, they failed to escape, and they rushed into a patrol car parked nearby. The monster was approaching to them. When they began to accept their death, the patrol car glowed blue white and disappeared into a mysterious space carrying them. When they were astonished, it was an alien that appeared in front of them. He was a Bravian who is an officer of the Space Police Organization that was responsible for the peace and order of the universe. He explained them that he was aimed at by ferocious aliens in the Space Prison Sargasso. He added that he had given them a battle machine Dag Beagle made by copying machines on the Earth in order to fight against Sargasso. They turned into Dagwon by the power of Bravian, and fought against space monsters. At that moment, the patrol car came in front of En. En grew into the car and turned into the Brave Robot Dag Fire, then beaten the enemy. However, the fight between the Brave Dagwon and the felonious aliens of Sargasso had just begun.

Following Gutsy Galaxy Guard's victory over the Zonder Empire and the 31 Primevals, a new threat makes their appearance on Earth. GGG—with Guy Shishio and the newly-constructed GaoFighGar—team up with their French counterpart Chasseur to battle the evil organization BioNet. Among Chasseur's ranks is Renais Cardiff Shishioh, a former BioNet cyborg with the relentless pursuit of destroying those who took away her humanity. But as GGG and Chasseur fight the BioNet, GGG's bases around the world are suddenly attacked, and the recently-discovered Q-Parts and the original Gao Machines are stolen by Mamoru Amami, who has been abducted and cloned by an even greater threat known as the Eleven Kings of Sol. Evicted from Earth by the United Nations, GGG must now travel to the far reaches of the galaxy to battle the Eleven Kings of Sol and save Mamoru before it's too late. (Source: ANN, edited)

After a slumber of 12 millennia, the Demon Empire returns to seize control of the Earth. Reideen, the giant robot-like protector of the lost continent of Mu, senses the evil presence and awakens within its golden pyramid, revealing to young Japanese boy Akira Hibiki that he is the one descendant of the ancient Mu people who must help Reideen save Earth. He was assisted by his friends, token girl Mari Sakurano (daughter of a scientist fighting the Demon Empire) and several members of his high school soccer team. (Source: AniDB)