This book is a wonderful companion to Wonder by Palacio but must be read after Wonder. It took the author a while to write this book and I found it useful to wait a bit after reading Wonder to read this book.
Three different, secondary characters from Wonder are narrators of the different sections of the book. Julian, the boy who taunted Auggie, narrates the first part of the book and the readers see him as a much more complex person that we would have imagined. Christopher was Auggie's best friend from toddler times until Chris moved away. Charlotte helped show Auggie around the first day of school and stayed friendly with him, but not as friendly as Summer was. Empathy, kindness and trust are strong themes in the chapter narrated by Charlotte.
I found the section about Julian at times sad and the part Summer narrates complex but very moving, and made me smile at the end. Big changes do not happen but life goes on, much richer as they year progressed.