Hangyang university in Seoul has set up some facilities for Muslim students. Here is some info from the university website: http://www.hanyang.ac.kr/goLink.jsp?.../english1.html Here is some information about Seoul's only major masjid: Seoul Central Mosque Here is the Korean Muslim assocation website with information on halal restaurants, Korean language classes, etc. http://www.koreaislam.org/notice.do?method=list There are a few websites addressing the history of Islam in Korea which stretch back to 900 CE. More recently, Turk troops who fought in the Korean war also engaged in Dawah reintroducing Islam to Koreans. Since then, there has been a modest community of Korean Muslims and expat Muslim workers, students, professionals.
One more thing about Korea, America has been highly influential there. American culture and christianity has prospered such that Evangelical/born again Christian communities are the most outspoken in Korea. And they also spread missionaries like flies. One can find Korean christian missionaries in Afghanistan along with the Nato troops. If your brother goes to Korea, he should prepare for dealing with Korean Christian missionaries who use American strategies of proselytizing.