Nadja
Nadja is the focus of the entire book, though she is not written about in the first part. She is described as a young, beautiful woman with startling eyes that draw you in. André meets her and is instantly intrigued. She enjoys telling stories about herself, though it is later revealed that the stories she had been telling were lies. In the end, she is admitted to a place that is supposed to bring her back on the road of sanity, though André believes she will only get worse.
André
André, or Andre Breton as he also is called, is both the narrator and the main protagonist in the book. As all the characters in the book, he is real. The book acts as his outlet to why and how the world is and functions the way it does, which he explains. He is a philosopher, specialized in something called surrealism. He ponders the reality of people, what defines people and who they really are through his encounters with people, heavily focused on Nadja.
The ghosted 'self'
The self is a person that André believes exists. This person is a person everyone has inside, the person we are working towards becoming. He explains it with the word "haunted", as our bodies are mere vessels that are inhabited by something other than ourselves. It is similar to Plato's "ideal" world, where everything has an ideal version to it.