Genshiken (げんしけん, Genshiken?) is a manga series by Shimoku Kio about a college club for otaku (extremely devoted fans of various media) and the lifestyle its members pursue. The title is a shortening of the club's official name, Gendai Shikaku Bunka Kenkyūkai (現代視覚文化研究会, Gendai Shikaku Bunka Kenkyūkai?), or "The Society for the Study of Modern Visual Culture". The series has also been adapted into an anime directed by Tsutomu Mizushima. The manga originally ran in Kodansha's monthly manga anthology Afternoon from June 2002 to June 2006, and has been reprinted in nine bound volumes. The ninth and final volume was released in Japan in December 2006.

Source: Wikipedia