What I've tried to do, both in the bios and the text, is consistently render all the non-native-English-speaking characters' ranks as their American army/air force equivalents, except when someone is specifically speaking to one of them in her own language - when Gryphon makes a point of addressing Mio as "Sakamoto Mio-shōsa" for effect, for example. However, as the fine print in the bios indicates, those are just translations - they all actually hold their proper ranks as they would be named in their home services.

This is slightly inaccurate in respect to the characters who are members of the Imperial Fusō Navy - as noted above, they should really have navy ranks in translation - but I don't know, maybe it's just because I learned it from the subs I watched before it occurred to me that it was off, but "Major Sakamoto" is just Mio's Name to me now. "Lieutenant Commander Sakamoto" seems weird. Hell, even now that she's been promoted I've made it a running thing that people still instinctively call her Major. :)

I'm dealing with this by waving my hands and assuming that, unlike the real Imperial Japanese Naval Air Service, the Imperial Fusō Naval Air Services officially uses army-style ranks when it does business in English, despite being part of the Navy (as I am given to understand real-life U.S. Marine Corps aviators do, even when serving aboard aircraft carriers). Interestingly, this solves a small problem the canonical writers made, in that Yoshika - despite also being a member of the Imperial Naval Air Service - is describe as a sergeant (gunsō) in the original TV series. Unlike the officer ranks, the Imperial Japanese Navy's enlisted grades did not have the same names in Japanese as the Army's - there was no such thing as a navy gunsō.

Meanwhile, native-English-speaking characters who are members of forces that use the Anglophone aviator ranks, like the Britannian RAF and Royal Farawayland Air Force, get to use their actual ranks, even though that's a bit confusing, because, well, at least they're in English. Fortunately, there aren't many of those, and Lynne Bishop, the most prominent one, would be a Warrant Officer either way.

For reference, this page has a handy chart for keeping the equivalencies straight, particularly with the British-style air force ranks, and here are guides to the way Imperial Japan (and thus Fusō) did their army and navy ranks back in the day. And the WWII Luftwaffe.

In a final twist, even non-translated, Shizuka's rank is ambiguous in the movie. She introduces herself at one point as a first-year Naval Academy cadet (who would logically hold the rank of midshipman, shōi kōhosei), but at another point she specifically says she's an "Imperial Navy sergeant" (Kaigun gunsō) - which makes no sense at all, since, as noted above, the Imperial Navy didn't have gunsō.

For our purposes here, I'm going to assume she was a midshipman, but when she chose to remain in Europe and switch to active duty with the 501st instead of returning to the Academy, she was converted into an Imperial Naval Air Service sergeant. And that works because of the aforementioned, already-in-place handwave about the Air Service using army ranks! So, go me, I guess?

Phew! Worldbuilding is a bit of work, even when someone else has done most of it for you. :)

--G.
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Benjamin D. Hutchins, Co-Founder, Editor-in-Chief, & Forum Mod
Eyrie Productions, Unlimited http://www.eyrie-productions.com/
zgryphon at that email service Google has
Ceterum censeo Carthaginem esse delendam.