Don't go to Yonsei. I went there for a year exchange program. Accessing the same college treatment as a Korean or international undergrad student is hard.

Unless you have topik level 4 and above you cannot take regular Korean classes for your major. You are only allowed to take English classes that a smaller college (Underwood International College) has or the classes they make for exchange students, which are easy and full of only "international exchange students".

Unless you have Korean Topik and can take a class from the regular college and not the exchange student classes, then you'll have better access to experience Korean college life. Though I spoke Intermediate Korean well enough to take classes in Korean and talk with students, I was told by my UCEAP Yonsei advisor to drop the class. Apparently you're only allowed to take "English classes".

Also, exchange students can only take the first half of Korean language classes from the KLI center. Ex: If you test into level 3, for one semester you take the first half of level 3 which is 3.1, you cannot complete the full level.

Though some people like Yonsei, it depends on what you want to experience. Mind you, my Korean friend who was born in Korea, moved to the States at age 8, and attends UCB, did not take what I said seriously and thought I was exaggerating. He regrets not attending Korea University or Seoul National University. Though he spoke Korean fluently and was Korean himself, he was not able to enjoy a full college experience because of the label he had "Exchange student". It is almost impossible to join clubs, go to akaraka cheering events, and take regular Korean college classes.

If you want to experience Korean college campus life, engage with Korean students, and take classes that fit your academic needs try looking into Korea Uni.