totsubo,
OK, you can use Japanese input methods by making symbolic links .
First of all, you have to make choice of an input method you want to use.
libCRIM.so.1.0.0 is a hand-writing input method for Japanese letters.
Using this method, you can also input Kanji directly.
libqjpn50pad.so.1.0.0 is a input method for Japanese "alphabet" (hiragana, katakana).
Maybe other input methods (libqjpnktnpad.so.1.0.0, libqjpnnumpad.so.1.0.0, libqjpnsympad.so.1.0.0) are useless for an English speaker. Even we Japanese don't use these input methods
Have you finished making a choice? OK, now make symbolic links.
For example, assume you select "libCRIM.so.1.0.0",
$ su
# ln -s /hdd1/usr/QtPalmtop.rom/plugins/inputmethods/libCRIM.so* /opt/QtPalmtop/plugins/inputmethods
Then reboot your Z.
The input method will appear on your taskbar...
HTH,