because people are strange and to some its a form of art... in which those people love that kinda art...(some people are just horn with a Y if u know what i mean -_-)
While ertic art had existed in Japan for centuries, "modern" hent*i exists namely due to the strict p*rnographic censorship in post WWII Japan. people started to draw erotic art which were technically able to pass by the censorship laws. the business started to boom in the 1970s, and the first hent*i videos started popping up in the 80s
