The genre started with Mitsuteru Yokoyama's 1956 manga Tetsujin 28-go (which was later animated in 1963 and also released abroad as Gigantor). Its inclusion is debatable however, as the robot was controlled by remote instead of a cockpit in the machine. Not long after that the genre was largely defined by author Go Nagai, into something considerably more fantastical. Mazinger Z, his most famous creation, was not only the first successful Super Robot anime series, but also the pioneer of the genre staples like weapons that were activated by the hero calling out their names ("Rocket Punch!"). It was also a pioneer in die-cast metal toys such as the Chogokin series in Japan and the Shogun Warriors in the USA, that were (and still are) very popular with children and collectors. Getter Robo, fo