By default, Asian text in Adobe-compatible PDFs is encoded with standard set of Adobe fonts.
I am not sure, but probably there are no actual fonts exist, just a standard alias, for substitution with available fonts by different systems.
For example readers for Windows, like Adobe Acrobat reader use kind of "MS Gothic" family in place of encoded "HeiseiKakuGo W5"
But Inkscape is different.
Inkscape does not know aliases for Japanese fonts at all.
So looks like instead of "MS Gothic" it chooses Helvetica, which ends up in Arial Unicode in Windows.
As a result, all the Unicode Latin strings in native Japanese text becomes deformed (Yes, Latin alphabet is widely used in Japan).
I tried editing alias files in Inkscape for Windows, but without detailed knowledge had no success in this.
Here are the fonts our system uses for generating standard PDF forms:
HeiseiKakuGo-W5-Bold-UniJIS-UCS2
HeiseiKakuGo-W5-Bold-UniJIS-UCS2-H
HeiseiKakuGo-W5-UniJIS-UCS2
HeiseiKakuGo-W5-UniJIS-UCS2-H
HeiseiKakuGo-W5-UniJIS-UCS2-HW
HeiseiKakuGo-W5-UniJIS-UCS2-HW-H
Probably, at least half of these are actually "MS Gothic". But I do not know exact rules for substitution used by Adobe.
By default, Asian text in Adobe-compatible PDFs is encoded with standard set of Adobe fonts.
I am not sure, but probably there are no actual fonts exist, just a standard alias, for substitution with available fonts by different systems.
For example readers for Windows, like Adobe Acrobat reader use kind of "MS Gothic" family in place of encoded "HeiseiKakuGo W5"
But Inkscape is different.
Inkscape does not know aliases for Japanese fonts at all.
So looks like instead of "MS Gothic" it chooses Helvetica, which ends up in Arial Unicode in Windows.
As a result, all the Unicode Latin strings in native Japanese text becomes deformed (Yes, Latin alphabet is widely used in Japan).
I tried editing alias files in Inkscape for Windows, but without detailed knowledge had no success in this.
Here are the fonts our system uses for generating standard PDF forms: W5-Bold- UniJIS- UCS2 W5-Bold- UniJIS- UCS2-H W5-UniJIS- UCS2 W5-UniJIS- UCS2-H W5-UniJIS- UCS2-HW W5-UniJIS- UCS2-HW- H
HeiseiKakuGo-
HeiseiKakuGo-
HeiseiKakuGo-
HeiseiKakuGo-
HeiseiKakuGo-
HeiseiKakuGo-
Probably, at least half of these are actually "MS Gothic". But I do not know exact rules for substitution used by Adobe.