The Japanese IME's I know of for Qtopia are anthy and nunome. AFAIK, neither of these is in OpenEmbedded, and I've already asked about using IME's compiled for Sharp ROM's on OZ. The answer was that the sharp-compat-libs only works with binary executables, where all input methods exist as dynamic libraries. So, the answer to your question is that until someone gets around to adding one of the above to OE, or compiles it themselves for OZ, there won't be any Japanese IME's available. I may attempt to do the latter (compile nunome for OZ) once I get KDevelop up and running.