One long and several short stories structured around the theme of loneliness.
In the series' first three-episode arc, Natsume encounters his most powerful yokai yet. Appearing again are Taki, the girl who can't see yokai herself but knows about them, and Mr Natori the actor/exorcist.
Two of the shorter stories also have returning characters -- the bullied orphan fox spirit (so sweet! I wish he would get a better deal) and Reiko herself.
For some reason the collection ends with a completely unrelated story about a high school girl who develops feelings for an unfriendly teacher. It is well done and fits the loneliness theme but is not fantasy, doesn't have any of the usual characters, etc. In short, I have no idea why it appears in this collection.