The film begins with a young man running while muttering over and over again, "Don't-" (Don't let it bring you down), the title of the film. These words are also a passionate message to the audience. A man and a woman, one chasing the other and the other being chased, a young man with a dream to make a film and the other with no time left. The love, desire, and fate of these people are depicted in this bold story. The final scene with "Love Me Tender" in the background is very moving.
After his wife and child committed suicide, Sasaki was so shocked that he quit his job and has been living a modest life painting. Then, by chance, he meets up with an old colleague and heads to the home of his colleague's wife, Sachiko, who is waiting for him. In fact, Sachiko and Sasaki have been having an affair for a long time, and that day they have sex next to their colleague as he sleeps. Sasaki also begins to have a physical relationship with Sachiko's younger sister.