Poet, novelist, and essayist. Born Obata Terumichi in Kanazawa, Ishikawa Prefecture, he was an illegitimate child adopted into the Muroo family. In his youth he worked as a page at a district court. His superior, who taught HAIKU on the side, introduced him to literature. In 1910 he left Kanazawa for Tokyo and, through his contributions to the journal Zamboa (Shaddock), came to know KITAHARA Hakushu (1885-1942) and HAGIWARA Sakutaro (1886-1942). Quickly becoming recognized as a born lyricist, he wrote short poems in a free style and slightly unorthodox classical language. His collections include "Ai no shishu" (1918, Poems of Love) and "Jojo shokyokushu" (1918, Short Lyrical Songs).
After he married in 1918, Muroo associated with novelist AKUTAGAWA Ryunosuke and began writing lyrical autobiographical novels. His first work in prose was "Yonen jidai"(My Childhood), which was followed by "Sei ni mezameru koro"(As I Was Awakened to Sex) and "Aru shojo no shi made"(The Death of a Certain Girl), all in 1919. However, as Japanese writers cultivated new ideas and techniques in their literature and expanded their vision and sought to deepen their introspection, he was somewhat isolated from the main current.
His longest novel, "Anzukko"(1956-57), was awarded the Yomiuri Literary Prize in 1958. He won the Noma Literary Prize for "Kagero no nikki ibun (1958-59, A Supplement to The Gossamer Years), a long novel based on the famous Heian-period (794-1185) diary "KAGERO NIKKI". Muroo also composed haiku and published several collections. In 1960 he established the Muroo Saisei Poetry Prize.