将数据从SQL导出到Excel文件（csv）时出现未知的UTF-8

Question

I'm going to export data from SQL to Excel file (csv). For now, i can exported data from SQL to Excel but it doesn't know Japanese language (it becomes ????? in Excel file that i export from SQL).

Here is data in SQL

ccode        country
AL           Albania
AD           Andorra
AO           Angola
BR           Brazil
JP           東京

Here is data in Excel file (csv) after i exported

ccode        country
AL           Albania
AD           Andorra
AO           Angola
BR           Brazil
JP           ????

Here is my coding to export data

<?php

//connection
include('dbconfig.php');

//create query to select as data from your table
$contents="ccode,country
";

//Mysql query to get records from datanbase
$user_query = mysql_query('SELECT * FROM countries');

//While loop to fetch the records
while($row = mysql_fetch_array($user_query))
{
    $contents.=$row['ccode'].",";
    $contents.=$row['country']."
";
}

// remove html and php tags etc.
$contents = strip_tags($contents); 

header('Content-type: application/vnd.ms-excel; charset=UTF-8');
header("Content-Disposition: attachment; filename=data".date('d-m-Y').".csv");
print $contents;

?>

Can anyone help me with this problem?

Thank in advance.