Did you think tentacle porn was a recent development? Or, for that matter, erotic manga? Not at all, as Japan possesses a long and glorious history of erotic art going back centuries (as in fact do most cultures), called 春画 / Shunga, which flourished particularly during the reign of the Tokugawa Shogunate.
I came accross an interesting representative sample, and some of the themes may be familiar to you, though some are perhaps more bizarre than contemporary works (unless you spend much time on /d/, in which case these subjects will all be familiar to you). There is even an illustration of someone using an ancient dakimakura. I am mirroring most of the images below, though I leave the illustration of man and his faithful companion as a dubious incentive to visit the originating site, if you dare.
This image is particularly famous: “The Dream of the Fisherman’s Wife”, “蛸と海女”, by the exceedingly famous 葛飾北斎 / Katsushika Hokusai, the artist responsible for the renowned ukiyoe print “The Great Wave off Kanagawa”, as well as “36 Views of Mount Fuji”. Strangely enough, most sources are silent on this aspect of his works.
I notice with envy that the ancients never had to deal with Japan’s tedious censorship regime.