The plot involves three strong-willed teenagers: martial artist Ryoma Nagare, rebel loner Hayato Jin and Judo master Musashi Tomoe, who pilot three specially designed combat jets which can be combined together into three different giant robots, Getter-1 (for flight combat), Getter-2 (speed advantage for ground\underground combat), and Getter-3 (strength advantage for submarine combat). They were assembled by Prof. Saotome, who conceived the Getter Robo project as a means of deep-space exploration; it became instead Earth's first line of defense against the Dinosaur Empire, a civilization of reptile-like humanoids who evolved from the now-extinct dinosaurs that roamed the earth millions of years ago. They have lived many years underground, and they now want to reclaim the Earth as theirs and destroy humanity.
The series was groundbreaking in the anime mecha genre: for the very first time, it introduced the concept of separate machines combining to form a Super Robot. Using three jets, Getter Robo could combine in three different ways to create three different versions of Getter Robo for different conditions and situations. This idea was originally discussed during the creation process for
Mazinger Z (the first Super Robot to be piloted internally), but was dropped and then developed for
Getter Robo. This idea of combination and transformation proved to be a very powerful concept that has been used in the super robot genre ever since. Also, by adding three pilots to the robot was able to add an element of teen drama, probably influenced by the already popular anime sci-fi team show
Gatchaman (better known in the U.S. as
Battle of the Planets,
G-Force: Guardians of Space or
Eagle Riders).
Dinosaur Empire 
