Linux Standalone and Japanese

Long story short: When I try to input Japanese in a text field all I get are ASCII characters. I've tried the old style GUI and the new Unity 4.6 UI system, to no avail.

So my question is: does Unity supports Japanese IME for Linux standalone builds? And if so which configuration would be supported?

I currently use an Ubuntu 14.10, with iBus and anthy. Japanese input works very well outside of my Unity game. I didn't try other Linux distributions, or other input methods (mozc instead of anthy, or SCIM instead of iBus) but if any of this would solve my issue I will switch.

I understand that there are higher priorities (like il2cpp) compared to this rather obscure use-case, but I really really don't look forward to building my own solution...