noun
captain (JASDF, JGSDF); lieutenant (senior grade; JMSDF)
Military rank; specific to Japan Self-Defense Forces. Equivalent to captain in the Air and Ground Self-Defense Forces, and to lieutenant (senior grade) in the Maritime Self-Defense Force.
彼は航空自衛隊の一尉に昇進した。
He was promoted to captain in the Air Self-Defense Force.
海上自衛隊の一尉は、他国の海軍では大尉
A lieutenant (senior grade) in the Maritime Self-Defense Force is equivalent to a lieutenant in other navies.
Compound of 一 (one, first) and 尉 (military officer rank). The rank naming system was introduced with the establishment of the Japan Self-Defense Forces.