The main character of this book is Charlie, the book is all letters that Charlie has written to his "friend". We dont know who the friend is. Charlie is a freshman in high school who has a very hard time making friends. He goes through rough times because his Aunt Helen and his best friend both passed away.
The other two main characters of the book are the two friends that Charlie finally made, Sam and Patrick. They are both seniors and they are step brother and sister. Sam is a sweet quiet girl, while Patrick is a little more outgoing.