I'm a librarian who loves anime, manga, and reading a wide variety of genres.
First story: Natsume investigates incidents of yokai getting their blood drained. He thinks the head of the Matoba exorcist clan is behind it – a theory supported by Nyanko and Natori's wariness towards him. Second story: Natsume and a bunch of yokai play shadow-tag. Third story: Unrelated to Natsume's Book of Friends. It's about a kid who gains amazing athletic abilities by drinking juice. He's secretly in love with a female friend of his, who he realizes loves someone else.
It's nice to finally meet the head of the Matoba clan, a character I enjoyed in the anime. However, this was very different from the usual Natsume's Book of Friends volume. I think Midorikawa does better with bittersweet short stories.
The second story is utterly and completely fluff. Nice fluff, with everyone playing tag with Natsume, who never got to do it with other human kids, but still fluff.
The third story, the one-shot, was an utter mess. Poor storytelling, plus a lack of focus. We have over-the-top stuff like the boy who gets amazing physical abilities from drinking ordinary juice, of all things, a lackluster romance, and a thief. Midorikawa has definitely improved since she wrote this.
(Original review posted on A Library Girl's Familiar Diversions.)