Apple Music Different Selection iPad vs iTunes?

Hi People,

I was playing around with Apple Music on my iPad Air 2 and noticed I could listen to all the songs from the Japanese iTunes store (at least most), however, as soon as I switch to desktop iTunes I can no longer listen to those Japanese songs without switching to iTunes Japan and creating a Japanese ID (as well as signing up for music separately).

Is this an intended feature or is this a bug?

I thought iTunes Music is supposed to be global. Are there any plans from Apple to fix this issue so I can stream Japanese songs - while residing in USA without having to pay double subscription and having two IDs?