I've updated the GNU coreutils site to reference the online Japanese version of the manual. The third "Getting Help" link on http://gnu.org/s/coreutils/ is https://linuxjm.osdn.jp/info/GNU_coreutils/coreutils-ja.html
BTW omething we should consider in future as well as translations is having multiple versions of the manual online, especially when the man pages reference them directly. cheers, Pádraig.
