We start with young troublemaker Kotaro Kirigakure skipping out on ninja training with his father Toubei. Naturally, said father is not pleased with this, causing a father-son spat that ends with Kotaro accidentally breaking a large stone that acted as a seal for Gokuark, one of the rulers of the "Daimakai"note . Naturally, upon freed, the demon king sets out to wreak havoc.
Or rather, he would if Eldoran, the defender of Earth, wasn't on the scene. He uses his powers to reseal Gokuark, who uses the last of his powers to send out his servant, Yaminorius III. Eldoran, in return, sends out the robot Ganbaruger to chase after him. A battle across the town ensues, causing Ganbaruger to split and vanish.
Later, Kotaro and his friends Rikiya and Yosuke are heading off to play baseball when suddenly, they see a crash. They then go over to find three robots just sitting laying in the middle of the woods. They end up jumping into the robots and get wrist watches that gives them all full-body suits, only for Yaminorius to summon up a "Makaijuu"note to attack the robots. The boys try to run away, only for Kotaro's dad to find them and insist that they fight. Eventually they get around to that, and combine their three machines, reforming Ganbaruger, and take out the Makaijuu. The day is saved!
...for about a minute before Yaminorius shows up again. Kotaro's dad tries to attack him, and gets turned into a dog for his troubles. then tries to do the same to the young trio, but Eldoran's power seemingly protects them. However, before retreating, Yaminorius warns them that his magic is still in effect, and should anybody find out their identities, it will override Eldoran's protection and turn them into dogs.
Thus begins the often-times wacky adventure to defend a small town from the invasion of demons.
See also The Brave of Gold: Goldran of its "big brother" franchise, the Brave Series, by the same creators, as it is similar in that it tells a comedy-focused story of an elementary-aged Freudian Trio, in contrast to most of the other entries in their respective franchise.
This show contains examples of:
- The Cameo: One episode features the appearance of Raijin-Oh and its pilots saving Kotaro.
- And that's not even counting how Taida makes a random background appearance at least every other episode.
- Color-Coded Characters: Unlike Raijin-Oh, this show plays it straight for the most part.
- Kotaro, aka "Yellow Ganba," pilots the yellow Go Tiger.
- Rikiya, aka "Red Ganba," pilots the red King Elephant. Revolger, however, is mostly blue.
- Yosuke, aka "Blue Ganba," pilots the blue Mach Eagle. That being said, Gekiryuger is equal parts red and blue.
- Kid Hero: Par for the course. In fact, Ganbaruger stands out as having the youngest team in the Eldoran series, with its protagonist having not even lived a full decade.
- Monster of the Week: Again, par for the course. Note that, at first, Yaminorius just randomly flipped through his dictionaries to summon specific Makaijuu, but then he does something similar to the previous series and makes them out of objects he finds after he temporarily takes his master, Gokuark's, essence into him until he can be revived.
- Secret Identity: Justified: if anybody finds out the real identity of the Ganba Team, they'll get turned into dogs, which would not only put a damper on real life, but also make it almost impossible to pilot their robots. They actually get found out before the halfway point by Rikiya's little brother Tetsuya, but thankfully they found Eldoran, who turned them back to normal, and since Tetsuya was half asleep when he saw, he wrote it off as a dream, saving them for the time being.