I am currently enrolled at Busan Universities Language School , but when I initially came and enrolled in did not receive a visa as i was only enrolled in 1 semester at the time and someone advised me i did not need one because i am of American nationality. I have now been here for over half a year and have been leaving and re-entering the country every 90 days. I would like to stay here and continue studying and hope to enter regular university soon. I’m not sure what i need to bring to immigration, or if it is even possible to get the visa while i am already here in Korea.Any help would be greatly appreciated thank you!