Friend (2001)

Despite their different family backgrounds, four friends grew up together in the wearisome years of the 70s. But as time goes by, each of them takes a different life path. After enrolling in college, Sang-taek and Joong-ho return to visit Dong-su (Jang Dong-gun) and Joon-suk (Yoo Oh-sung), only to find one of them in jail and the other on drugs. Slowly life takes difficult turns where friends become rivals in the crime world.