DOCX to EPUB, mixed latin/asian fonts

[jindroush]

Problem: Input DOCX with Asian/Latin mixed paragraphs, but resulting EPUB does not contain/reference asian fonts.

Explanation:
I have DOCX file, which uses three fonts: Times New Roman, Calibri and MS Mincho (asian).

The default fonts are set to Times New Roman/MS Mincho, 12pts. Almost all of the styles are linked to the main style which, again, has explicitely set the fonts like this.

The fonts are displayed correctly in Office365, in the Save options I have Embed Fonts/Subset fonts/Do not include system fonts. In the DOCX are 4 fonts included (visible in fonts subdir and in fontTable.xml - three different Calibris and one MS Mincho). I tried all four combinations of subsetting/system fonts.

Conversion to EPUB works like a charm, but the resulting file contains 6 fonts: Three Calibri and three Times New Roman. The japanese characters are not "escaped", "styled", or anything, they're just put inline with latin characters... In the original text (document.xml) there are explicit hints the text is eastAsian.

<w:r w:rsidR="009F0743" w:rsidRPr="009F0743">
<w:rPr>
<w:rFonts w:hint="eastAsia"/>
<w:lang w:eastAsia="ja-JP"/>
</w:rPr>
<w:t>お手玉</w:t>
</w:r>

EPUB displays japanese characters (maybe they're included in Times New Roman), but they look differently to what I want and I'm not sure if this would work on Kindle.

What am I doing wrong?

[kovidgoyal]

IIRC docx input doesnt have support for font hints. Feel free to come up with a patch for it, not something I care about personally.