'Stoker' refers to the person who tends to the fire in a steam engine - it's also known as 'fireman', especially on steam locomotives.
Marine Engineering ratings are still sometimes called 'stoker'. So here, it's quite possible that Hibiki's 'stoker' was the one to... fire up her engine, so to speak.
Traditionally, someone who shovels coal into steam boilers. Given that the Fubuki-class were propelled by steam turbines I'm not sure if their "stokers" were more akin to "fuel technicians" than the classic "beefy sweaty guys with a big shovel," but I'm not well versed on the era's ship engine technology and operation methods.
EDIT: Apparently it took me more than 1.3 minutes to type that...
Traditionally, someone who shovels coal into steam boilers. Given that the Fubuki-class were propelled by steam turbines I'm not sure if their "stokers" were more akin to "fuel technicians" than the classic "beefy sweaty guys with a big shovel," but I'm not well versed on the era's ship engine technology and operation methods.
Stoker was a first a job description and then morphed into a title for engineering ratings over time.
Stoker had already become a a generic term for engineering personnel by even WWI, at least in the Royal Navy, even before ships moved to oil they were referring to engine room crew as 'stokers' with second, fist, etc amended as they increased in seniority. This increasingly had little to do with the mans actual job, and pretty much nothing to do with it after the switch over to oil, but was just basically a title denoting the department he served in (engine room crew). "Stokers" ran most day to day aspects of engineering plant and the most senior of them oversaw it's overall operation in conjunction with or in the absence of more highly trained engineering technicians (referred to as Artificer) and commissioned officers.
At the time of WWII it went roughly (lowest to highest): Stoker 2nd class Stoker 1st class Leading stoker Petty Officer stoker Chief Petty Officer stoker
I can't comment on the IJN, but given it's considerable nerd crush on the Royal Navy for most of the early 20th century I would suspect it was similiar. The US Navy didn't use the term though instead classing the first three non-specialized entry level grades as 'fireman' and then moving onto differing titles upon reaching the first grade of petty officer.(machinist mate, boilermaker, etc for engine room personnel).
He is my stoker.And what's more, you're a Lady aren't you, Akatsuki?No way.He's an acquaintance, right? How about introducing me too-My identity is finished?!I wonder if he'll be happy to take the bentou...I was cut off?!Is not a joyful and sorrow-like youth necessary for an adult?Hey, Hibiki! I heard that you got a new sailor?Immediate answer?!