Of those four, only Rodan didn't wind up as the focus of a Godzilla versus movie in the Heisei era. As the book explains, Toho's plans for Godzilla vs. Mechagodzilla II may be why that was the case.

who refers to himself as a “Heisei culture expert.” Yamashita was absorbed in amassing keychains modeled after a local mascot popular around 1990. His attachment to the mascot, whose head is ...