Internal WordPress engine simply creates permalink based on title. Non-latin characters are encoded based on RFC 1738(or its PHP implementation as urlencode function) and it produces long, non-readable URL look a like
http://ko.wikipedia.org/wiki/%EB%AC%BC%EB%A6%AC_%EC%A3%BC%EC%86%8C_%ED%99%95%EC%9E%A5 . This encoded URL still works and can be decoded by browsers. It is very hard to read specially all the stats uses URL as a key. To prevent this, simply change the suggested permalink all the time or uses digit form like /?p=123.
But if you want not to be bothered, this plugin can be a solution for Roman presentation as Korean pronounciation.
Based on code of the np4v(Vietnameses version of this plugin) from Quang Anh Do. Korean-Roman presentation table is adopted from
http://xpg.in/tcm/thread.php?topic_id=771. Thanks bhleejw.
For Korean explanation about this plugin or any suggestion, please visit
http://masterkeykorea.com/nicer-permalinks-for-korean