Friend (2001)

AKA: Chingoo
Synopsis:
Friend (Chingoo) is a 2001 South Korean film directed by Kwak Kyung-taek. At one time, it was the highest-grossing South Korean movie of all time, but has since been surpassed. This film is the director's experience about his friends, a semi-autobiography set in his hometown, Busan, and the actors speak with a strongly accented Busan dialect.
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.
Part-01
Part-02