I picked up April's month of Nakayoshi for the bonus goodies, which are 3 mini notebooks featuring CCS art. The paper on the inside of the books are on the thinner side and a bit see through. The books themselves are also quite thin with not a lot of pages. I don't think they're particularly functional as notebooks, since ink might bleed through to the other side. (Pencil should be fine.) I mostly got it for collection purposes. The art is very cute.