Can you try setting the DB Charset within wp-config.php?
define('DB_CHARSET', 'utf8_general_ci');
define('DB_COLLATE', 'utf8_general_ci');
Have a read of this first though: https://codex.wordpress.org/Editing_wp-config.php
It can cause problems to an already existing blog to add those lines into wp-config.php, so use with caution.
Are you importing this through WordPress or manually through something like PhpMyAdmin?
Also, are all the tables are collated correctly?