I have a sister who is a year older and one who is five years younger, and I think that this book has one of the most honest portrayals of how complex sibling relationships are while growing up.
There's one chapter in the book that just tells a story about June and her older sister Greta celebrating April Fool's over the years, from the both of them planning schemes on their parents when they were younger, to Greta then playing pranks on June, to the one year that Greta does nothing at all. It's so simple, yet so telling of the changing dynamics of their relationship. I feel that this chapter can be a short story in itself.
As June says at one point, there are different kinds of love. There are also different kinds of heartbreak, and losing your best and only friend is one of them. There's a lot of pain in this book, because June lost the one person that she felt truly understood her, and then felt further betrayed when she realized that he had a whole side of his life that was kept from her.
I honestly wasn't captured by this book from the beginning, and I was a bit wary of reading a book about a relationship between a 14-year-old and a much older man. But as I kept reading, I fell in love with June, her insights, her flaws, her strengths and her growth. I'd probably say that this is a book about the complexities of love and relationships. This is a really beautiful story.