In the first years of the Shōwa era, Japanese society was characterized by conflicting ideologies: on one hand, the Marxist theories strongly permeating the cultural environment, and on the other hand, a growing nationalistic feeling that was insinuating in every field. By the beginning of the 1930s, following the invasion of Manchuria, the governmental control over the media became quite total. Heroes from mythology and from the past were often symbols of the new Japanese warriors, and propaganda animations increased. The situation completely changed after the bombings on Hiroshima and Nagasaki and with the occupation of Japan by the Allied Powers, when new regulations imposed democracy in every social and cultural field. It did not take long for the world of animation to get back into the scene, and the great animators who had been active during the war period, such as Masaoka Kenzō and Ōfuji Noburō, were able to produce their most refined works, thanks to this new innovative atmosphere.