Genshiken (げんしけん) is a Japanese manga series by Shimoku Kio about a college club for otaku (extremely obsessed fans of various media) and their lifestyle.

The title is a shortening of the club's official name, Gendai Shikaku Bunka Kenkyūkai (現代視覚文化研究会), or "The Society for the Study of Modern Visual Culture".

Common plot points include such otaku-centric activities as the buying and creation of dōjinshi, fan-made manga usually of erotic content; convincing a character to try cosplay (dressing up as characters from manga, anime, or video games); the creation of plamo (plastic models that must be assembled); visiting Akihabara, Tokyo's electronics shopping district; or attending the biannual Comic Festival ("Comifes"), a reference to Comic Market ("Comiket"), Japan's single largest anime- and manga-focused fan convention.

Since the anime is co-produced by Sega Sammy Holdings, the Guilty Gear video game series is heavily referenced, with actual gameplay sequences being shown multiple times, Ohno cosplaying as Kuradoberi Jam, and other minor references.

Numerous other non-Sega/Sammy properties are also referenced throughout the anime, but their names are changed slightly, such as The King of Fighters '95 being alluded to as COF 95 and Capcom vs SNK 2 as "S-Cup".

The anime, however, has been criticized for having "excessive script variances" with its English dub translations, such as injecting English-specific references like "talk to the hand" and for inconsistently including liner notes.

Pretty Menma tells Kaoru that his dead father's intention is making him succeed in the "Food King Wars", a battle of restaurants around the world that is held every 4 years.

[7] This series is also spun off into its own Internet radio show, manga (serialized in Monthly Comic Alive) and a drama CD.

As the story of Genshiken progresses, focus is also placed on Saki Kasukabe, a determined non-otaku who initially struggles to drag her boyfriend Kousaka out of the club, and Chika Ogiue, a self-professed otaku-hater who feels a deep-seated shame and self-loathing toward her own interests and hobbies.

During the course of the series, the reader bears witness as the group grows in its cohesiveness over time, and bonds form between the characters as they begin to see themselves as more than fellow club members, but friends as well.

After Sasahara, Kousaka and Kasukabe graduate, the series shifts focus to three new club members: The self-conscious Yajima, the energetic-yet-annoying Yoshitake, and Hato, a fudanshi who cross-dresses to fit in better and go unrecognized by his normal classmates.

The first new episode was released with Kujibiki Unbalance DVD Box 1 on December 22, 2006, with the two subsequent installments following on February 23 and April 25, 2007, respectively.

[11] On April 23, 2007, it was announced on the Genshiken homepage that a second anime television series would be produced, including the character Ogiue, who had been introduced in the OVA episodes.

[15] The series premiered on July 7, 2013 and includes the opening song "Genshi, Joshi wa, Taiyo Datta" by Sumire Uesaka and the band Kabuki Rocks.

The book introduces the character of Ranto Hairu, the rich grandson of one of Japan's most influential businessmen, as he takes over the student club organization with the intention of getting rid of any elements he views as unsavory.