Kujibiki Unbalance (くじびきアンバランス, Kujibiki Anbaransu?), as it exists in the real world, is a 3-episode OVA from the highly popular 2004 anime Genshiken, as well as a series of 3 light novels by Genshiken anime collaborator Michiko Yokote. Within the world of Genshiken, however, Kujibiki Unbalance is a popular ongoing manga and 26-episode anime adaptation, which is eagerly watched and discussed by the main characters. These same characters also purchase associated products and adult-oriented dojinshi based on the series, which constitute the motivation for some of the "club activities" held by the Genshiken. Genshiken characters who are fans of Kujibiki Unbalance tend to refer to it by the shorthand name of Kuji-Un (くじアン, Kujian?).

The series is, in essence, a compilation of many of the standard themes found in certain kinds of anime and manga series: childhood promises as the source of relationship drama, the influential yet shadowy Student Council, somewhat contrived scenarios designed to push the plot forward, mid-series "recaps" to remind viewers of previous events, and a sudden crisis that threatens to alienate the main characters and jeopardizes the outcome of the series. Kujibiki Unbalance is meant to be a very stereotypical anime series, serving as both an homage to and a parody of the kinds of series that the otaku of Genshiken would enjoy.