Two girls make friends and spend all of their free time together. After a while, one of them develops a physical attraction to her friend and freaks out about it. It is also established that both girls like boys too.
Jamie notices that everyone suddenly likes her favorite band, so she changes it. Problem is, people copy that, too. So she keeps switching, and the music keeps getting worse.
This book is way funnier than I just made it sound.
We start out with the diary of someone called Fats, who is writing about his friend Corky, who appears to be losing it. Then we learn some more about Corky, who does indeed appear to be a bit off. But the whole thing kind of fell apart for me when I found out who Fats was.