I can't seem to get Japanese font to display correctly in Brave. It does display correctly in both Firefox and Chrome. I believe the fonts are from the font-droid-ttf package.
I downloaded Brave with Snap, so I suspect it might a Snap related issue, but I'm not sure, so I thought I'd go here. If it is their or Brave's issue, I'll be happy to go bother them.
I'm on the MATE version of Solus.