something funny about the way noda draws their trousers in the manga is that this is purely for 'fan service'. meiji 19 1886 uniform trousers were not as low as they're drawn here. in fact, low-rise pants defeat the purpose of their functionality.
the concept of low-rise pants is fairly modern and only serve aesthetic purposes. high-waisted pants, especially when speaking about military uniforms, served a functional purpose. the pants were supposed to sit at the natural waist/over the navel (they were also meant to be worn with suspenders), this provides better support, makes mobility easier and more comfortable since it gives the hips and thighs more room for movement , and keeps the pants from riding down or their shirts to become untucked during physical labor.
you can see the difference in the live action!
(excuse the awful screenshot)
in general, back in the 1900s pants were high-rise, a low-rise design would've been unthinkable, especially for a military uniform.
i just thought this was a fun fact. the history nerd in me prefers the live action's accuracy, but the pervert in me thinks noda's decision of drawing their pants like that is sexy as hell, what can i say ┐(. ❛ ᴗ ❛.)┌