Seiki no Kai (世紀の会, The Century Society) was an influential art research and discussion group briefly active in early postwar Japan, from 1947 to 1951. It was established and led primarily by the author Kōbō Abe, and focused on cultural collaboration between its members, all of whom were artists, writers, or critics in their twenties. Because there were few opportunities for young people to publish or exhibit their work in these years, the group primarily focused on organizing lectures and discussion groups on relevant cultural topics – or as they phrased it, "20-something culture by 20-somethings, for 20-somethings."[1] The group was influenced by two senior members, painter Tarō Okamoto, who was interested in Surrealism, and the avant-garde critic Kiyoteru Hanada, whose discourse engaged Marxism, along with the founder Kōbō Abe, who was steeped in existentialism. As a result, most of the group's events investigated topics related to these ideas.
In the later years of the group, members were increasingly influenced by the concept of sōgō geijutsu ("total art"), or multimedia works produced through collective action. They produced several low-cost collaborative publications with limited distribution. The group eventually split up when Abe and others opted to join the Japanese Communist Party and pursue more active involvement in the political sphere. Despite only being active for a few years, the group was nonetheless a key educational source and meeting point for young creative people in Japan, especially at a time when there were few resources available. It is commonly thought to be a precursor to later avant-garde artistic collaborations and collectives in Japan.