Who is Will Cash from Just Listen and what is their importance?

Will Cash is described as a dark-haired, self-involved young man, who has a reputation for being a jerk. He drives a Jeep, plays guitar in a band, and dates Sophie..... with whom, he is abusive. Will later tries to rape Annabel, and he even manages to talk his way out of a sticky situation when they are discovered by Sophie, blaming Annabel instead. Sophie supports him fully until he is charged with an attack on Emily as well. Will is charged, and when other girls come forward, including Annabel, he faces jail time.