Storywriter. Born in Tokyo, the son of a court noble. After studying at the Gakushuin, he entered the Imperial University of Tokyo, but left school before graduation. He became acquainted with Naoya Shiga and others while studying at Gakushuin Senior High School. In 1910, together with Shiga, Takeo Arishima, and others, Mushanokoji established "Shirakaba" magazine, where he published works energetically. After publishing "Atarashiki mura no seikatsu" (The life in a new village) in 1918, he created a community village in Miyazaki Prefecture in which he lived until 1925. In 1937, he became a member of the Japan Art Academy. He served as Chairman of the Dramatic Literature Division of the Nihon Bungaku Hokokukai (Patriotic Association for Japanese Literature). After the war, he was removed from public office under the Occupation Purge. In 1951, he received the Order of Culture. His representative works include "Omedetaki hito" (Good-Natured Person), "Yujo" (Friendship), "Aru Otoko" (A Certain Man), and "Shinri sensei" (Teacher of Truth). Mushanokoji was also active as a painter, founding an art exhibition.