Plot is one of the important elements of any story. According to Anne Lamott plot "is the main story of your book."
This is an exercise in thinking. Which came first the plot or the characters? Different writers will answer plot while others will yell characters. A good story needs both.
For me when I start a book I have a general plot in mind. A very general one. Then I find characters who might carry this plot to the end of a book. These characters are vague with some traits. For me writing means an interaction of characters with the elements of the plot. Each drives the other and I am the conductor.
My style of writing is quite different from Anne Lamott's. I begin by telling myself a story and once I have this down, I have both plot and character but nothing I would show anyone else. Once this is done I begin layering. I have friends who struggle over each word before they come to the end. A friend and I once did an experiment. She is character oriented and the plot comes from her characters. I'm the opposite. I write drafts. She writes and rewrites each chapter until it's perfect. The strange thing is that it took us the same amount of time to complete the story.
So, for you which comes first - the plot or the characters? A good story needs both.