You have to put together the various files you want, like the mka audio.  Ugh.

It isn't dual audio, it's JP with folders containing other languages that you would have to mux in.
Most players don't allow you to add another audio track like you can with subs.
And don't say to use 'x' player to add the audio because most won't download another player.

what good is Japanese commentary without English subtitles? Unless you know Japanese it's just wasted space.