What is "chogokin"

is Japanese for "Super Alloy" and is a fictitious material which first appeared in Go Nagai's Mazinger Z manga and anime. It was later adopted by Popy in 1972 as the name of a new line of die-cast metal robot and character toys sold in Japan. The first of these toys was the "GA-01" Mazinger Z, which, in spite of questionable engineering that led Popy to offer a free replacement campaign, ignited a craze that changed the face of the Japanese toy industry in the 1970s. Bandai, the parent company of Popy, continues the Chogokin line to this day, branded under their own name.