Seventy-three years ago today, on July 24, 1952 (June 3, 1952 in the lunar calendar), the socialist mystery novel emerged in Japan. Socialist mystery novels are a genre of Japanese novels that emerged in the 1950s. In 1946, in order to strengthen the logical reasoning of "detective novels", Kagi Takataro renamed it "mystery novels". After the reform of Japanese writing, the word "detective" was abolished, and the literary world officially adopted the name "mystery novel". The prosperity of mystery novels was closely related to the popularity of Japanese television and the prosperity of weekly magazines at that time. Mystery novels were divided into Benstyle and Declension before the war in Japan. Benstyle emphasizes logical reasoning. The declension school focuses on the description of science fiction and abnormal psychology, and the content is mostly eerie, absurd, and exaggerated. In the 1950s, the novelist Seihiro Matsumoto initiated a new stage in the development of Japanese mystery novels. He broke through the fixed mode of the original and the declension school, based on reality, and published "Point and Line" in 1957. This representative is called the pioneering work of the socialist mystery novel. Representative writers of the socialist mystery novel are Matsumoto Seihiro, Mizumi, Maraiyi, Shigego Kuroiwa, and Masako Tokawa. They are accustomed to placing the plot of the detective case in a broad social context (especially World War II), delving into the spiritual world of the criminal, exploring the social reasons for the murder crime, revealing social contradictions and dark phenomena, and criticizing the evil of war. The works have a strong sense of the times and critical spirit. In terms of expression methods, it pays attention to the use of logical reasoning techniques to create suspense. The plot is tortuous and interlocking, which is intriguing. Representative works include Matsumoto Seihiro's series of novels "Japan's Black Mist" and "Sand Tool", Mizumi's "Flower Tombstone", "Fog and Shadow", etc. These works were once extremely popular and formed a frenzy of mystery novels. Socialist school of mystery novels has improved the ideological and artistic nature of mystery novels, making them enter a new artistic world and become an important part of contemporary Japanese literature. To this day, many writers have inherited the tradition of this school and created a large number of mystery novels.