chief petty officer (IJN); petty officer first class (US Navy)
Historical Imperial Japanese Navy rank, roughly equivalent to a US Navy petty officer first class. Used in military contexts.
See also: 上等兵曹 (じょうとうへいそう)
During the war, he served aboard a destroyer as a chief petty officer.
上等兵曹 is a higher rank (senior chief petty officer) in the IJN, while 一等兵曹 is one step below.
Compound of 一等 (first class) and 兵曹 (petty officer), a rank term used in the Imperial Japanese Navy.