Okay, I had a hard time deciding between 4 or 5 stars for GIRL PARTS, so I'll go with 4.5, giving the book the benefit of the doubt with a 5 since I can't do half numbers on Goodreads. 
 As for the plot, GIRL PARTS is about a futuristic society where people have become increasingly reliant on virtual technology. All school is conducted via the internet, and teenagers often have the majority of their friendships over various online social networks. In fact, the novel begins with a teenage girl committing suicide in front of a crowd of virtual onlookers. 
 David, the son of a wealthy entrepreneur, was amongst the "audience" of the suicide website. Concerned that he has so dissociated himself from normal human emotion, his father enlists him in an experimental therapy. David will have a female android, called a Companion, complete with everything but "girl parts". He will use this robot to learn to forge a "real life" relationship to cure him of his "dissociative disorder". 
 Charlie is another teenage boy in therapy for dissociation. While he declines the assistance of a Companion, he soon becomes intermingled with David's android, Rose, as they bond over their realization that neither truly feels like a "real" part of modern society. 
 GIRL PARTS is an intriguing mirror of modern society (to the extreme) and illustrates the depths of loneliness that can be felt, even amongst a world more interconnected (virtually) than ever before. 
 I found the characters to be realistic and relateable. And while the ending wasn't exactly what I expected, I think it's fitting, given the point of the novel as a whole. 
 After reading so many paranormal-type YA books, GIRL PARTS was definitely a refreshing change. This is a book I would definitely recommend to anyone is interested in the aforementioned description!