Fifth grader Seiji was just a normal kid, until he became pulled into a conflict of galactic proportions! A UFO attacked his town one day, and after hearing a voice speak to him, he found himself in the company of a police car-turned-robot named Da Garn. It is one of eight Brave Fighters who have protected Earth since its infancy – all of which became Brave Stones and are scattered throughout the planet. It’s up to Seiji to find and awaken the other Brave Fighters, command Da Garn to battle the alien invaders, and keep his secret safe from his classmates!
In the 21st century, the marvels of technology have led to both breakthrough inventions, and criminal syndicates which employ mecha robots to commit crimes. To combat this threat, the Brave Police Project and a special mecha with Super A.I. were created. Six months ago, young Yuuta stumbled across the top secret mecha – named Deckerd - and built a relationship with it, helping it learn to have a heart. Now, the time has come for Deckerd to have its memory wiped. However, even after the event, in the midst of a battle Yuuta’s voice triggers Deckerd’s memory once more and the two fight valiantly together. Though young, Yuuta is sworn into the police force to always be by Deckerd’s side! Together with J-Roader, Deckerd’s support vehicle which fuses with it to allow him to fly; and a Build Team of other transforming robots; Yuuta and Deckerd will help bring peace to the city and take down bad guys where they stand!
Let's face it - if you've seen one Sunrise mecha series you've likely seen them all, as they all are remarkably similar. J-Decker and Da-Garn fit better than usual because they involve a young boy who's somewhat accidentally charged with protecting the world, with a sentient robot by his side.
Both shows are about a kid who teams up with a giant robot who transforms into a police car to fight off assorted villains and monsters. The protagonists in both shows expand their teams over time, so that the kid in each winds up leading a whole team of giant robots.
Deep in the recesses of space, the powers of good and evil are in a constant battle for the cosmos. Earth has remained out of the struggle until now, when the Geisters – evil energy lifeforms – invade the planet and search out host bodies and treasures to steal. Luckily for humanity there’s hope – the energy lifeform Exkaiser of the Space Police descends to the planet and inhabits the family car of young Kouta! With luck, Exkaiser and other transforming robots will help put a stop to the Geisters and save mankind!
While there are plenty of mecha anime out there with different themes, Da-garn and Exkaiser both involve a young person inexplicably becoming entwined in a battle between their giant robot benefactor and the baddies (from space!) With a similar feel and tone, you'd definitely like one if you liked the other.
Both shows revolve around a struggle for special totems (stones in the case of Da-Garn, discs in the case of Go!) which awaken & control giant transforming robots. Both shows feature young boys as the leaders of the heroic groups, and have very similar designs for the heroic mecha. While these two shows are so similar that it's scary, the similarities between them is less surprising when you realize that the Brave series were based on designs originally intended for Transformers decades ago.