Comic Market 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 December 21, 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.
Comiket is focused primarily on the sale of dōjin: non-commercial, self-published works. Approximately 35,000 circles (a term for groups or individuals who create dōjin) participate in each edition of Comiket.
Different circles exhibit on each day of Comiket; circles producing works on a common subject, such as a particular media franchise or manga genre, are typically grouped on the same day.
The most common item sold at Comiket is dōjinshi (self-published comics that are often derivative fan works based on anime, video games, and other media, legal according to Japanese law shinkokuzai), though circles also sell dōjin soft (video games), computer software, music, novels, clothing, and other goods.
Since Comiket's inauguration, sample copies of all works sold at Comiket are collected and archived by ComiketPC, with over 2.1 million works having been archived.
According to en.wikipedia