Space Ironmen Kyodain

Space Ironmen Kyodain (宇宙鉄人キョーダイン Uchū Tetsujin Kyōdain?) was a Japanese Tokusatsu science fiction superhero television series. The show, like numerous others of its type and era, were produced as a joint effort between manga artist Shotaro Ishinomori and Toei Company producer Hirayama Tôru. It premiered in 1976 and ran for 48 episodes.

The plot of the program involves an alien empire from the planet "Dada" called the "Robot Army Corps". When they kidnap a human scientist, Dr. Hayami, and two of his three sons and force him to improve their technology, he has no choice but to go along with them, despite his deep anger, resentment, and guilt.

One year later, their empire sufficiently advanced, the Robot Army Corps return to Earth, ready to put their plans into action—however, two heretofore unknown robots charge in and stop their invasion cold. It is then revealed that Dr. Hayami programmed the personalities of his two kidnapped sons, Jouji and Ryouji, into these super-powered robots to both stop the Robot Army he was forced to work for, and care for his youngest son, Kenji. Jouji and Ryouji, now "Skyzel" (as in "sky) and "Granzel" (as in "ground"), are armed with awesome strength and powerful shape-shifting abilities, able to transform into a jet and a car respectively. With these abilities, they carry on their father's legacy and fulfill his wishes.

Tropes:

 * Merchandise-Driven
 * Robot Buddy: Gonbesu GA-49. It separates into two parts - its head, like a flying saucer, and its body, which resembles a huge bowling ball - when fleeing or attacking an enemy.
 * Shout-Out:
 * The planet Dada is maybe a shout-out to the art movement of the same name, as the series is described as having a very odd design, reminiscent of Dada art.
 * It received one in Lucky Star, where its opening song was used as the ending theme of the first episode.
 * And again with many elements of Kamen Rider Fourze, most notably the title character's Skyzer-esque helmet, borrowing from the series.
 * ...Aaand then Toei announced a Kyodain/Fourze Crossover.
 * Sibling Team: Skyzel and Granzel.