- Executive Meddling: Go Nagai originally wanted Sayaka to be the 4th spazer pilot but was opposed by director and co-plotter of the series, Shingo Araki, who wanted and indeed did introduce his own character to the series, Maria.
- Marth Debuted in "Smash Bros.": In various countries, Grendizer got aired before its predecessor Mazinger Z. So for many, Koji Kabuto was Duke's friend before being The Hero of his own series.
- An even bigger problem, however, lies in the fact Koji's name was changed in a lot of foreign versions (for example, in France and Italy where Grendizer was absurdly huge, Koji was called "Alcor" after the star in Grendizer) and then got his normal, unmodified name back in other Mazinger works that aired after Grendizer was huge. These being the pre-Internet days, people didn't pick up on the fact that it was supposed to be the same character and so audiences assumed that Mazinger was simply a very blatant, cheap knockoff of Grendizer.
- Recycled: The Series: In 1975 Toei Animation produced a Super Robot Genre movie called Uchu Enban Daisenso. Go Nagai, who did the designs of characters and mechas, liked the concept so much that he decided to recycle and improve his designs and create a new Mazinger anime based on the movie ''.
Trivia / UFO Robo Grendizer