Choson Pururetaria Yesul Yongmaeng (Korean Proletarian Artist League, 조선 프롤레타리아 예술 가동맹), also known as KAPF (Koreen Artiste Proletarienne Federation, 카프) is a left-wing guild formed in 1925 when two smaller left-wing literary guilds (Yongun-sa and Pascue) merged in July. The official founding date is August 23, 1925
You can read a little bit more about the KAPF in the book, “The Proletarian Wave: Literature and Leftist Culture in Colonial Korea, 1910-1945” by Sunyoung Park