First held in 1975, Comic Market (typically shortened as Comiket or Comike) is a doujin market convention occurring in August and December of every year. The event was created as a location for independent creators to sell their works to the public, typically as "circles", groups of creators working on a single project. Circles are allowed to sell a wide variety of works, such as music, novels, computer programs, and hand-made crafts. However, the most popular types of work tend to be anime/manga and computer programs/games, with the two groups accounting for around 57% of works during Comiket 84.
Although it is an event built around highlighting independent creators, not every attendee is required to be independent. Corporations are allowed to attend the event as vendors, although corporate booths are fairly limited in number and location within the event venue. Typically, attending corporations are related to anime, manga, and video games, with some attendees even being former doujin circles, such as Type-Moon. Additionally, corporations with ties to the fields of technology and doujin works are common attendees, especially Microsoft, Google, art-website Pixiv, and Niconico.
Comiket events tend to draw in a considerable number of attendees, with events since the mid-2000s averaging over 500,000 non-creator attendees across a three-day period. This popularity has played a notable role in popularizing a number of series originally released at Comiket, including the no Naku Koro ni series, Fate-precursor Tsukihime, and most notably the Touhou Project series. This fan following also tends to bolster currently popular media, with fans often seeking out works based on popular properties, or cosplaying as characters from such properties while at the event.