Jūran Hisao (久生 十蘭, Hisao Jūran; 6 April 1902 – 6 October 1957) was the pen-name of a Japanese author of popular fiction in Shōwa period Japan. Hisao Jūran was a pioneer in the use of black humor in Japanese literature. His works reflect his extensive knowledge of a wide range of subjects, and displayed extraordinary skills, and range from mystery tales to humor, and both historical and contemporary settings. His real name was Masao Abe (阿部 正雄, Abe Masao).
Source: “Juran Hisao”, English Wikipedia (CC BY-SA 4.0), excerpt