Unicode doesn't be inserted into DB

[eluser]cleansugar[/eluser]
CodeIgniter recent version:

In database.php, utf8 and utf8_general_ci are setted.

in model.php

function insertData($idname, $password)
{
$data = array('id' => '한글', 'password' => 'password');
$this->db->insert('mydb', $data);
}

In database '???', 'password' are inserted

How can I insert Unicode into database?