Remember, doujin (同人), as in doujinshi (from doujin zasshi) means something of a group like the apostles, by implication...
Remember, doujin (同人), as in doujinshi (from doujin zasshi) means something of a group like the apostles, by implication fanworks
By contrast America already had a term for “erotic comic based off established characters produced outside of copyright”, “Tijuana Bible”