, also known as , was a Japanese ethnologist, linguist, folklorist, novelist, and poet. As a disciple of Kunio Yanagita, he established an original academic field named , which is a mixture of Japanese folklore, Japanese classics, and Shintà Â. He produced many works in a diversity of fields covering the history of literature, folkloric performing arts, folklore itself, Japanese language, the classics study, Shintà Âology, ancient study, and so on. Yukio Mishima once called him the "Japanese Walter Pater".
Orikuchi was born in the former Nishinari, à Âsaka (now part of Naniwa-ku, Osaka). After graduating with a degree in Japanese literature from Kokugakuin University in 1910, he started to teach Japanese and Chinese classics at junior high schools. In 1919, he was employed as a part-time instructor in Kokugakuin University. In 1922, he was promoted to professor. In 1924, he was hired as a professor at Keio University as well; afterward, he taught at two different universities until he died. As a poet, he and Kitahara Hakushu established a tanka magazine called Nikkà  ("Sunshine") in 1924. In 1925, he published , his first tanka book, which is highly esteemed.
In 1934, he received a doctorate for his study on the Man'yà Âshà «. He also established the . As a folklorist, Yanagita was known for rejecting every sexual subject; Orikuchi, in contrast, was very open-minded to these matters. He became a model for the protagonist in Mishima's short story , while his novel Shisha no Sho was the basis for a film by Kihachiro Kawamoto.
Orikuchi was a homosexual (nanshokuka). Harumi Orikuchi (), scholar of Japanese literature and poet, was his de facto partner. Harumi died in Battle of Iwo Jima.