We used this as a textbook and it absolutely does not work as a textbook. It's just a bunch of excerpts from Japanese books, which does not allow for a frame of reference or even context. Some are literary, some are essays, some are scientific-ish.
I really don't know what could be this for except vocabulary (there's a glossary at the end).
I'm sorry that I have nothing good to say about this. I think the Sky Tree excerpt was the most interesting one.