sentences:  In 1928, the Japanese Proletarian Arts Federation (全日本無産者芸術連盟, Nippona Artista Proleta Federacio, known as NAPF) was founded, bringing together the Japan Proletarian Artists Union (日本プロレタリア芸術連盟), the Labor-Farmers Artists Union (労農芸術家連盟), and the Vanguard Artists Union (前衛芸術家同盟).NAPF was largely the responsibility of two up-and-coming writers called Takiji Kobayashi and Sunao Tokunaga, and the organization's newsletter "Battleflag" (戦旗) published many influential works such as Kobayashi's "The Crab Cannery Ship" (蟹工船) and "March 15, 1928" (一九二八年三月十五日) and Tokunaga's "A Street Without Sun" (太陽のない街).Another important magazine was "Reconstruction" (改造) which published writings from Ryunosuke Akutagawa and Yuriko Miyamoto, who had just returned from the Soviet Union.