Mori was born 1908 in Tokyo and graduated from Keio University. Afterwards, he studied painting at the Painting Research Society and Joint Research Society. 1931-34, Mori traveled to Paris, where he absorbed contemporary European painting. After his return to Japan, he joined the Independent Art Association,

and was named an associate of the Association (he left in 1939). He then joined the Free Art Association, in which he remained a member until 1964. He also participated in the founding of the Subject Art Association. Mori taught at Musashino Art University from 1951 to 1981. He died in 1997.