As far as I know, this is the only non-English official Wing Commander guide which wasn’t a straight translation of the regular versions. I can’t tell you who the author was but it was published by Locus in 1996 and generously supplied by Loaf for scanning:-
It’s the usual story with these Japanese guides in that I can’t say too much else about it, but it’s well presented and looks to be fairly thorough with wingmen details, ship/weapon stats, mission guides and everything else you would expect. It doesn’t have the interviews that were in the regular English guide but does have the bonus of being in full colour throughout. It’s now scanned and available to download for anyone who wants a look.