Although CCleaner offers a Japanese language installation option, the programme itself does not properly display file names or registry keys that are composed of multibyte or unicode strings.
Since Windows is (at least from Windows 2K onward) unicode based, this is a fairly serious programming error. It is no great trick to make a programme that properly displays multibyte or unicode strings even if the basic programme itself is ascii or English oriented. 2xexplorer is one readily available example as are any of the common browsers including Mozilla and Opera.
EHK