It is classified as such due to its:
* Target audience: The story is aimed at readers aged 8-12.
* Themes and characters: It deals with themes of friendship, family, identity, and growing up, relatable to children in that age range.
* Writing style: The language and narrative structure are appropriate for middle grade readers.
Although it touches on themes of grief and loss, it does so in a way that is sensitive and appropriate for its intended audience.