Space Ironmen Kyodyne premiered in 1976 and ran for 48 episodes it centred around an alien empire from the planet “Dada” called the “Robot Army Corps” who kidnap a human scientist named Dr. Hayami and two of his three sons. The Robot Army Corps aim to force Dr. Hayami to improve their technology and weapons. He has no choice but to go along with them for the safety of his sons.
The timeline then jumps one year forward where the Robot Army Corps return to battle Earth with all the upgrades Dr. Hayami has provided for them. Expecting to win easily they are shocked when two unknown robots charge in and stop their invasion cold. It is then revealed that Dr. Hayama programmed the personalities of his two kidnapped sons, Joji and Ryuji, into the two Cyberroids to combat the Robot Army and care for his youngest son, Kenji. Using their Cyber Graphy to assume the forms of Joji and Ryuji, the older brother Skyzel and his younger brother Grounzel carry out Dr. Hayami’s wish as the Kyodyne.