To give you a very general idea of what the movie 친구 is about, it is a movie that talks about 4 friends that eventually grow up and end up in a very different life from one another.
The thing that I found very interesting about both stories is that despite the striking difference between their setting, one in Busan and one in U.S., these boys all go through the same passages in life.
친구 starts from a scene where the boys are very young, as young as 13. This is the age that they are probably like the boys in the Body. At this age, these boys show much similarities to the boys that are in "The Body". They joke around with each other, and talk about things that we find to be quite silly in such a serious manner. For instance, in the movie Stand by Me, the boys talk about whether Goofy is a dog or not. In the case of 친구, the boys talks about whether a professional swimmer or a turtle would be faster.
This talking about things that are not really important as if it really matters to them, is one similarity that I found interesting in those movies.
Another similarity I found in these movies is the family background. 준석 is a character that is like a father to those boys, protecting them from outer sources of influence such as teachers and bad boys. He, a perfect match with Chris, has a father who is a gangster. Like Chris, who had a drunkard for father.
The main difference between these movies is the point of life that the story focuses on. Unlike Stand by Me, 친구 is more about the people those boys become after they grow up and the life that they lead. Two of them becomes a gangster, a rival gang at that, one becomes a elite, and the last becomes an ordinary restaurant owner. 동수 ends up dead, murdered brutally by 준석' s gang. 준석 goes to prison for life.
Still, the movie 친구 relates with the movie Stand by Me in a way that the directors for both movies would not have noticed. Remember how "Friends Drag you down"?
Well that line is explicitly shown in the movie친구. 동수 becomes a gangster only because of the influence of 준석, whose father was a gangster also. He ends up dead because his friend dragged him down.
A very interesting characteristic that 친구 has with Stand by Me is the future of Chris. The actor who played Chris, River, gets addicted to drugs. Well, 동수, a match for Chris, also goes through periods in which he suffers from drug addiction.
They both have a similar tone, the tone of nostalgia and that friends can't really last forever regardless of what you think of them in your mind.
친구 is a great movie, a personal favorite of mine and one strangely similar to Stand By Me.