The space pirate Geisters have invaded Earth. The leader of the Space Police Kaisers, Exkaiser, came to Earth in pursuit of the Geisters with his team. As alien energy life forms, the Kaisers fuse into various vehicles. Kouta Hoshikawa, a boy in the third grade, learns that Exkaiser is fused to his dad's sportscar and cooperates to keep his identity a secret. Exkaiser's friends include the Raker Brothers, who are twins fused to bullet trains, and the Max Team, who are fused to a jet plane, a racecar and a drill tank. They routinely patrol the Earth in the form of vehicles, but when the Geisters appear, they transform into giant robots to fight.
Meanwhile, the Geisters have fused into dinosaur robots. Led by Dino-Geist, they go after the Earth's treasures. However, since the Geisters are unfamiliar with the culture of this planet, they use television as a source of information. If they hear the word “treasure" to describe something, they will attempt to rob it regardless of whether it is electricity or flour. Kouta teaches Exkaiser Earth's strange customs too. Their friendship and courage crushes Geister's evil schemes one after another.
It is a moving story about a growing friendship between a giant robot hero and a boy. The first installment in the Brave Series!
