A hyper-sexual person who is very much likely to sit on a table or fall asleep there.

Dōjin is a japanese word which is used to describe a group of people with same interests. here is it's kanji (同人). please get don't get it confused with Dōjinshi (同人誌) which is used to describe fanmade works which are created by people who have similar interests. while you may see these words used to describe Hentai manga but keep in mind that this is the traditional definition