Not a solution, but a comment: it's usually considered necessary and sufficient for WIndows to have the Japanese language added.
What happens if you use an up to date version of Acrobat or Reader? Version 7 is really far too old to work properly on Windows 8.
Hi Test Screen Name,
Japanese language has already been added before the document was generated.
The same thing happens on Adobe Reader XI.
Guess this is not a compatibility issue, because my colleague with the exact same programs and Windows 8 could view the bookmarks.