so, i am much less convinced about this one. the rules for
capitalisation in english are sometimes a bit fuzzy...
oxford style guide, for example, begins: "usage is divided over
adjectives based on nationality." very often in these cases we don;t
uppercase - do you write about "roman numerals" or "Roman numerals"?
in this specific case, the packages being discussed are not even
japanese! they are simply packages categorised as being "japanese".
considering also that we are talking about how that will lead to
packages having a "ja-" stem, not "Ja-", i think uppercasing here would
be unhelpful.
jmc