Seems like purevpn provides S Korea IP address but I'm afraid it's not free (http://www.purevpn.com/vpn-service/southkorea.php) . In fact I doubt you can find any freebies offering Korean IP address. While you search for free VPN service please note that such Providers are more likely to log your activities and serve contextual ads while you're connected. They're also more likely to use your usage habits to tailor future ads to you, have fewer exit locations, and weak commitments to privacy so if logging and privacy are important to you, you may want to avoid them.