There's a reason why middle school and high school teachers love teaching this book: it's got a healthy dose of history, but it's written in a way that's easy to understand. Okay, sure there's the occasional SAT word thrown in there, but nothing that makes you go running to your dictionary every other minute.
Though the language is pretty accessible, Wakatsuki Houston and her husband are still writers, and that means they've got a couple of writerly tricks up their sleeves that might make you scratch your head for a second… like whole chapters written in italics. It's the stuff of English teacher dreams.
Plus, there's a pretty thorough exploration of the whole internment experience, including some painful examinations of the psyche of Japanese-Americans (and Caucasian Americans too). This stuff isn't exactly lightweight material, so it takes a willing reader to get into the deep end with the writers.