* [[Time Skip]]: A slight one in Chapter 56, which was created and released as a bonus together with the Japanese "Genshiken 2" box-set. The chapter told us what the characters had become, and what's going on the Genshiken club right now.
* [[Twelve-Episode Anime]]: Two seasons' worth, plus the three OVA episodes.
* [[Unintentional Period Piece]]: The series is a snapshot of the Japanese ''otaku'' subculture as it was at the time it was first published / aired. The references are contemporary, and it notably deals with the ''[[Moe]]'' boom and (to an extent) the "mainstreaming" of otakudom around the middle of the [[Turn of the Millennium]]. The gap between the old guard and the new generation is [http://ogiuemaniax.wordpress.com/2011/06/24/the-appearing-and-disappearing-wave-of-generational-change-in-genshiken-ii-volume-1genshiken-volume-10/ increasingly evident] in ''Nidaime'', where the idea of "otaku" has gone from something of an internalized, somewhat shameful identity to a (relatively) unstigmatized descriptor of someone who enjoys his or her hobbies with a shameless, fiery passion.
* [[Unlucky Childhood Friend]]: Kasukabe, much to the surprise of the others, seemed to be like this with Kousaka until he agreed to date her.
* [[Unstoppable Rage]]: Early in the series when Madarame placed cat ears on Kasukabe.