He was born as a son of Baron Masaaki Tomii, the president of Tokyo Imperial University of Legal and a draft member of Japanese Civil Law.
When he was young, his father hired Keita Gotō as Akira's home teacher.
Akira Tomii graduated Tokyo Imperial University, and served as the Japanese Consul in Mukden, China, in 1915.
He served as Japanese Ambassador to Argentina from March 1941 to January 1944, while also serving as non-resident Ambassador to Paraguay and Uruguay.
His daughter married Yasuo Ishizaka, a son of Taizō Ishizaka, the president of Toshiba and Japan Federation of Economic Organizations.