Drunken Angel - Akira Kurosawa

After a battle with rival criminals, a small-time gangster is treated by an alcoholic doctor in post-war Japan. The doctor diagnoses the young gangster's tuberculosis, and convinces him to begin treatment for it. The two enjoy an uneasy friendship until the gangster's former boss is released from prison and seeks to take over his gang once again. The ailing young man loses his status as gang boss and becomes ostracised, and eventually confronts his former boss in a battle to the death.