The story of the novel is set during the Peace Preservation Law of 1925, which targets those who believe in "Marxist" ideology. Proletarian writer Takiji Kobayashi chooses the harsh working conditions of a crab cannery ship as the subject of his next novel, which draws the attention of the special police task force charged with monitoring ideological threats. Two spies are sent to monitor his activities.

(Source: Anime News Network)