An action/adventure anime series created by Aeon and Takara and aired in 2002.
In the future robots are commonplace, and a tournament exists where Battle Robots are pitted against each other in battle. A boy named Akira Akebono wishes to win the Titan Belt by using the robots designed and built by his grandfather, Hajime. Akira fights using the Animal Unit; Bulion, Eaglearrow, and Drimog, until one day Hajime gives him a new robot, Ryugu. Ryugu is just as stubborn as Akira and the two clash, however he can also combine using the Cluster System with the new dragon robot Daigu to become Daigunder.
Akira and Ryugu become better partners and the team does well in the tournament. Along the way they're joined by three more robots, the Dino Unit; Bonerex, Despector, and Trihorn, who Hajime remembers he created earlier before making the Animal Unit.
- Combining Mecha: Almost all the prominent robots in the series can combine in different ways and combinations.
- Dragon Knight: Ryugu is based on a knight and combines with a robot dragon to become Daigunder. The first part of his name is even the Japanese name for dragon.
- Heel–Face Turn: DragoFlame and DragoFreeze join Team Akira after their leader abandons them.
- Interspecies Romance: One episode had Eagle Arrow develop a crush on a human woman studying the aurora. He never tells her this or that his Fighter Mode was the stranger who saved her from her fall.
- Panthera Awesome: Bulion, a blue lion and team leader of the Animal Unit.
- Pokémon Speak: Daigu is capable of saying other words, yet seems to prefer only shouting his name.
- Reasonable Authority Figure: Mr. Spinklestarber is the commissioner of league who enforces the rules. When meeting Akira, who technically didn't have all the robots required for the test, allows him to take on the condition he have less points. Meanwhile, he disqualifies Team X and Team Akira when it turns out both were added to a higher ranked tournament due to Ginzan hacking the system, but allowed Team Akira to keep their points since they were unaware of Ginzan's actions.
- Shoulder Cannon: Daigunder with his Dragon Cannon.Daigunder: Dragon Cannon!
- Those Two Guys: Tigamaru and Rogamaru, they're never seen apart when they try and cause Team Akira trouble.
- Vitriolic Best Buds: Eagle Arrow and Drimog frequently bicker and mock each other, but don't hesitate to have each other's back.