For Koreans 회식 is a very important part of working life. Every so often, you should go out with your co-workers and your boss and have some food, drinks and fun to get to know each other or to celebrate important events.
The differences between 회식 at my first hagwon and the hagwon where I work now are quite different. At my old hagwon, we held 회식 every time a (foreign) coworker left. Although, really what it was, was just a dinner. Korean teachers usually ducked out of the office and claimed they were busy. The forign teachers went only for the meal and bailed as soon as our plates were cleared. Sometimes small amounts of beer were consumed, but everyone felt a little awkward under the eyes of our very shy and very religious director who would host the dinners (and say only 2 sentences which seemed quite rehearsed because her English was quite poor for a director of an English school).
Here at the new school they don't make it easy to back out. Everyone goes, and we even dragged a non-drinking Korean co-worker once, even though she begged not to come. We also skip the whole dinner thing and go straight to the bar. Not to say we don't eat of course. Korean HOFs usually require food is ordered with a drink. And we order copious amounts of fried chicken, sausage, golbengi and the like. Our director leads the drinking and the bosses walk around making sure everyone's glass is topped off. Of course, they don't pour drinks until your glass is empty, so it's not uncommon to hear "One Shot!" and be expected to finish half a glass of beer so they can pour you the next one.
Our director really likes to make cheers, so every time a new dish comes out, he invents a new cheers. He also encouraged us to do a waterfall while drinking our beer. Every time I thought the end was near, a new 3000cc pitcher was ordered. Slowly, people started to sneak out as the evening progressed. This time I stayed until the end. Everyone except the bosses wound up in a cab to Hongdae (which is close to a 30,000 won cab ride from where we are past Jamshil) but since my friend was in town I had an excuse to escape. I am a little curious where the rest of the night went for the rest of them, but at the same time, I'm glad I wasn't there to witness it...