No, there aren't any leauges WITHIN Korea. The only the we have going is the Commanders Cup. However, if you are used to paying 300-500 dollars to play in PSP etc..there are leauges in other countries, Malaysia, Phillipines, China, and Thailand which including roundtrip ticket, paint, hotel, and food are about the same price as a PSP tournament entry fee alone. go to http://koreapaintball.webs.com/
it will link you up with a Paintball group some planning is going on there. So bring your marker and passport.