Comiket

Quoting from The Other Wiki: "Comic Market (コミックマーケット, Komikku Māketto), more commonly known as Comiket (コミケット, Komiketto) and sometimes Comike (コミケ, Komike), is a biannual dōjinshi fair in Tokyo, Japan. A grassroots, DIY event focused on the sale of dōjin (self-published works), Comiket is a not-for-profit, volunteer-run event administered by the Comic Market Preparatory Committee (ComiketPC). Inaugurated on 21 December 1975, with an estimated 700 attendees, it has grown to become the largest fan convention in the world, with an estimated attendance of over half a million."

The convention takes place twice a year, at the Tokyo Big Sight.

Anime and Manga

 * Hanaukyo Maid Tai, episode 5.
 * Lucky Star, episode 12 - Konata complains that it's changed from a friendly get-together into a marketplace over the years. This little adventure provides the page image for Doujinshi.

Anime and Manga

 * Comic Party uses "ComiPa" to drive its plot.
 * Genshiken has "ComiFes".
 * Yuru-Yuri has "Comuket".

Web Original

 * Fenspace has a "Cosmic Party", based on the Comic Party anime and game that reference Comiket.

Anime and Manga

 * When aliens steal the Tokyo Big Sight in Mao-chan, the building is described as the home of a convention loved by otaku instead of being named.