em-utf8.pl

#!/usr/bin/env perl
use utf8;
use strict;
use warnings;

binmode(STDOUT, ":encoding(UTF-8)");

use EBook::MOBI;
my $book = EBook::MOBI->new();
$book->set_encoding(':encoding(UTF-8)');

# These two lines work OK
$book->add_mhtml_content("<p>Here is some English text - Hello there!</p>\n");
$book->add_mhtml_content("<p>Here is some German text - Viele Grüße!</p>\n");

# These do not, showing garbled text when viewing in an eReader
$book->add_mhtml_content("<p>Here is some Chinese text - 你好!</p>\n");
$book->add_mhtml_content("<p>Here is some Japanese text - お元気ですか!</p>\n");

$book->add_mhtml_content("<p>End of text.</p>\n");

$book->make();

# Printing the raw mHTML shows the encoding is correct
$book->print_mhtml();

$book->save();