Sanada (Takashi Shimura) is an alcoholic doctor, a drunken angel, in postwar Japan who treats a somewhat young, small-time hood named Matsunaga (Toshiro Mifune), after a gunfight with a rival syndicate. The doctor diagnoses the young gangster with tuberculosis. He convinces Matsunaga to begin treatment and quit boozing and womanizing. The two enjoy an uneasy friendship until the gangster's former boss, Okada, who is also the abusive ex-boyfriend of the doctor's female assistant, is released from prison and seeks to take his gang over once again. In the meantime, Sanada continues treating his other patients, one of whom seems to be making progress against tuberculosis.