...Sometimes Kuniyoshi would depict cats in fully anthropomorphised form. They would walk around in costumes doing everything that humans do. While these types of illustrations are really fun to look at, there is also a deeper reason for their existence. During the early 1840s, the Tokugawa Shogunate believed that their political hold was starting to loosen. To reassert power they introduced the Tenpō Reforms. These were a series of strict and oppressive policies that aimed to strengthen their control. The Reforms included a ban on representations of kabuki actors, courtesans and geisha. For the Tokugawa Shogunate these professions represented luxuries which society could not afford and by depicting them, artists were said to be purposely provoking society through subversive ideas.
To get around this censorship Kuniyoshi would often illustrate famous kabuki actors in animal form; frequently hiding small clues that could hint at an actor's true identity. While the Reforms certainly brought about many limitations for illustrators, they also pushed them to think up new and inventive ways to communicate with their audience. Kuniyoshi's prints were hugely popular at the time and kabuki fans enjoyed trying to solve the visual clues that helped them identify each actor.
[http://illustrationchronicles.com/Obsessed-with-Cats-The-Ukiyo-e-Prints-of-Utagawa-Kuniyoshi]