Murai was born in 1905 in Gifu Prefecture. He studied at the Department of Art at Bunka Gakuin University with Ikuma Arishima and Hakutei Ishii. He then left to visit France and traveled in Europe extensively, absorbing Christian art as well as the avant-garde movements such as Piet Mondrian’s geometrical abstraction.

In 1932, Murai returned to Japan, where he participated in the monthly series of group exhibitions titled “A New Era of Western-Style Painting.” These exhibitions also featured the works of Kaoru Yamaguchi, Rokuro Yabashi, Saburo Hasegawa, Q Ei and Yozo Hamaguchi. Murai was a member of the Free Art Association, but distanced himself after the war. He was a founding member of the Modern Art Association. He died in 1999.