use Encode;
use Devel::Peek;

print "U+5F4C as a regular Perl character string (UTF-8 flag on):\n";
my $str = "\x{5F4C}";  
Dump $str;
printf "=> is%s alphabetic\n\n", $str =~ /\p{IsAlpha}/ ? "":"n't";

print "same character in Shift-JIS legacy encoding (UTF-8 flag off):\n";
$str = encode("shiftjis", $str);
Dump $str;
printf "=> is%s alphabetic\n\n", $str =~ /\p{IsAlpha}/ ? "":"n't";