noun
doujin circle; fan club; hobbyist group
A group of like-minded people who create and publish self-produced works, typically manga, novels, games, or music, often for sale at events like Comiket. The term is strongly associated with Japanese otaku culture.
彼女は同人サークルで漫画を描いている。
She draws manga in a doujin circle.
コミケに参加する同人サークルが増えている。
The number of doujin circles participating in Comiket is increasing.