I'm a Korean. I'm currently taking up pre-med course.
I hope this post could helps you.
Korean medical schools are both in undergradute course(6years) and in graduate course(4years). First, undergraduate courses are required high school's record, college enterance exam score(like SAT in U.S) and individual or group interview in general. Second, graduate courses required high GPA, MEET score(Medical Education Elegibility Test) and individual or group interview in general. Take note that requirements are different from schools.
I think you should ask specific requirements for foreign applicants to schools where you are interested in.
All korean medical schools are very competitive and hard to get into.
Only top of 1% korean students apply medical school annually.
I think medicine schools in graduate course are less competitive than medicine schools in undergraduate course.
I can't imagine foreigners enter medical school in Korea.
Because most lectures teach in Korean. Students must have a proficiency in Korean both writing and speaking. But they use textbooks written in English normally. Tuition fee is approximately U.S $4000~$5500 per semester in undergraduate course and U.S $8500~$10800 per semester in graduate course. (Two semesters per year)
I think the advice for foreigners trying to get into a Korean medical school is about the same as for a foreigner trying to get into a Japanese med school; don't bother. It's almost impossible for citizens to get in, so you could imagine it's borderline impossible for foreigners, regardless of language fluency.
I think GPA and academic back ground are the most important for the evaluation. Unlike American universities, Korean universities are not really consider extracurricular activities. But volunteer work experiences are could be helpful.