You should check out the information on Binmode: ( http://www.icewalkers.com/Perl/5.8.0/pod/func/binmode.html )

binmode(STDIN, ":shiftjis");
binmode(STDOUT, ":YOUR_DESIRED_OUTPUT_ENCODING");
[download]

and probably the Encode module: http://www.ayni.com/perldoc/perl5.8.0/lib/Encode.html

http://www.ayni.com/perldoc/perl5.8.0/lib/Encode.html

In case you can read Japanese: http://www.fl.reitaku-u.ac.jp/~schiba/perl/perlEncoding.html

It is possible to specify or guess the encoding of the file that you are working on, and these links should hopefully put you on the right track. I recently had a similar problem and the above listings led to the solution. However, it isn't precisely clear to me what your problem is: just parsing a japanese encoded page? viewing the results? Hopefully this is of some small help.