>where I can go for Japanese input support?
You can use "Anthy".
If you have already installed SCIM, you will need "Anthy" and "scim-anthy".
http://sourceforge.jp/projects/anthy/files/
http://sourceforge.jp/projects/scim-imengine/files/
( And, "skim" is optional choice to show input status panel on KDE desktop.
http://sourceforge.net/projects/scim/ )
Another choice is to use combination of "uim" and "Anthy".
http://uim.freedesktop.org/wiki/UimDownload
Good Luck !