In 1972, Go Nagai, another of Japan's greatest manga creators, defined the super robot genre with "Mazinger Z", which was directly inspired by the former series. He had the revolutionary idea to create a mecha that people could control like a car, while waiting to cross a busy street. The concept became "explosively popular", making the manga and anime into a success. The series also was the genesis for different tropes of the genre, such as the idea of a robot as a "dynamic entity" that could join with other machines or humans to become unstoppable. Anime critic Fred Patten wrote that almost all mecha anime plots, such as monster of the week shows, were actually metaphors for re-fighting World War II, and defending Japan and its culture from Western encroachment.