Translation guide
A military rank above second lieutenant and below captain. In Japanese contexts, the equivalent rank depends on the service branch and historical period. For modern Japan Self-Defense Forces, the rank is 一等陸尉 (Army), 一等海尉 (Navy), or 一等空尉 (Air Force). In historical Imperial Japanese military, it was 中尉. When referring to foreign militaries, 中尉 is commonly used as a translation.
Referring to the rank of first lieutenant in the present-day Japan Ground, Maritime, or Air Self-Defense Force.
First lieutenant in the Japan Ground Self-Defense Force (JGSDF). Literally 'first class land officer'. Used for army first lieutenants.
彼は一等陸尉に昇進した。
He was promoted to first lieutenant.
First lieutenant in the Japan Maritime Self-Defense Force (JMSDF). Equivalent to a navy lieutenant junior grade or first lieutenant depending on context. Literally 'first class sea officer'.
一等海尉が艦橋に立っていた。
The first lieutenant was standing on the bridge.
First lieutenant in the Japan Air Self-Defense Force (JASDF). Literally 'first class air officer'.
一等空尉が飛行隊を指揮している。
The first lieutenant is commanding the squadron.
Referring to the rank of first lieutenant in the Imperial Japanese Army or Navy (pre-1945).
First lieutenant in the Imperial Japanese Army. Also used for the equivalent rank in the navy (sub-lieutenant or lieutenant junior grade). This term is still used in historical contexts.
祖父は陸軍中尉だった。
My grandfather was an army first lieutenant.
Translating 'first lieutenant' when referring to a rank in a non-Japanese military, such as the US Army or British Army.
Standard translation for first lieutenant in foreign armies. Note that in some navies, this may correspond to 'lieutenant junior grade' or 'sub-lieutenant', but 中尉 is widely understood.
彼はアメリカ陸軍の中尉です。
He is a first lieutenant in the US Army.
Loanword from English, sometimes used in fictional or informal contexts, but not standard in official translations.
ゲームでファーストルテナントに昇格した。
I got promoted to first lieutenant in the game.
In English, 'first lieutenant' can be a naval rank (often a senior lieutenant or executive officer). In Japanese, naval ranks use different terms. For a ship's first lieutenant (executive officer), use 副長 (ふくちょう) or 先任士官 (せんにんしかん) depending on context, not 中尉.
In the JSDF, 一等陸尉 (first lieutenant) wears two cherry blossoms with one stripe on the collar. This may help in visual identification.