By Peter Dickinson.
I found this story very reminiscent of "Rachel in Love", for reasons that should be obvious shortly after starting the book. It was quite readable, but I didn't think it was exceptional. It's a peculiar kind of dated sci-fi where the future has "shapers" before it gets away from tapes as storage media. This may have bothered me and interfered with my enjoyment of the story more than I am willing to admit.
An okay story, but not really strong. Not really recommended.