I have been trying to setup Japanese input on elementary. After many hours of Googling around and installing and uninstalling packages I have made it work with IBus and the Anthy input method. The way I made it work was by installing anthy and Ibus and then running
im-config and selecting IBus as the input method. Unfortunately, once I do this I can no longer type at all on Slingshot. Everything except Slingshot seems fine thus far.
I also tried setting things up with fcitx but to get that working I had to remove IBus completely which seemed to eliminate some important packages, some stuff related to System Settings, so I decided not to use that method. Plus fcitx added a new icon on the wingpanel which is quite ugly.
Furthermore, with both IBus and fcitx, mozc didn't work, which works alright on Ubuntu 16.04. This is bad because I prefor mozc to Anthy.
I really want to use Elementary, but I need Japanese input to work and I can not get a satisfactory setup working.