Borders is an excellent middle grades graphic novel with substance. It is the story of an indigenous mother and son going to visit the daughter who has moved away. They have an issue at the border crossing station and end up in limbo. You'll have to read it to discover the problem and how the mother and son view it differently. 

This is poignant and realistic, and I think it will prompt you to consider a different point of view and issues with border definitions and the idea of citizenship in our society. Full of heart and lovely illustrations, I highly recommend!