[1] Ichimura was born, with the family name Hamaguchi,[2] in Nagasaki on 10 June 1930.
As a young adult Ichimura moved to Tokyo, where he studied for a year at Nihon University, took various jobs, and chanced to meet Shōtarō Akiyama, who aroused his interest in photography.
Ichimura won a special award at the First International Subjectivism Photo Exhibition (国際主観主義写真展, Kokusai Shukanshugi Shashinten), held at Takashimaya in Nihonbashi, Tokyo, in 1956.
He quickly moved to nude photography, and had his first solo exhibition, "Love & Lost", in Fuji Photo Salon in 1963.
From the late 1970s Ichimura branched out to photographs of Japanese iconography and landscape, particularly that of his native Nagasaki.