He was Minister of Defense from July to December 2012, and is professor at Takushoku University and member of the Congressional Forum for New Japan.

[2] After graduation, Morimoto served with Japan Air Self-Defense Force until 1979 when he joined the Ministry of Foreign Affairs.In 1992, he left the Ministry of Foreign Affairs and became a chief researcher at Nomura Research Institute (from 1992 to 2001).

[2] Morimoto was appointed defense minister on 3 June 2012 in a cabinet shuffle, replacing Tanaka Naoki.

[4] As an international political scientists, specialised in National Security, he has attended a number of expert committees and advisory councils held by the Japanese government.

[5][citation needed] He was instrumental in implementing the Three Principles (Transfer of Defence Equipment) policies in 2014, and the launch of Japan's only international defence trade show and conference, MAST Asia.