"Jinrui wa Suitaishimashita - Heijou Unten" (Humanity has Declined - Normal Operation) by Tanaka Romeo. These are short stories that took place after the original series ended (volume 9), with the same unnamed heroine and the same casual writing style, a great bonus for fans of the original series.
It was great to see the unnamed heroine back in action, and also most of the original characters (except one) made an appearance in this volume. All the characters were the same as before and all the fairies behaved the same as before, although there is some subtle progress regarding one character coupling. For readers looking for character development, this volume had just the right chapter for that purpose.
More likely, people were looking for what new mischiefs that the fairies have done, and this volume does not disappoint. From folklore/forklore collection to amusement parks with real jet engines in roller coasters -- life is great when making things fun is the primary reason for existence, and making things safe is a secondary consideration. Consistent with the casual "keep calm and carry on" style found in previous volumes, (mostly) nobody panics despite how reckless things may be. "Humanity has Declined" is one of few books where opposing queens enjoy afternoon tea while war between two cities are in progress. It's all very relaxing to read if you don't think too much about what bizarre state the cities are in, thanks to the fairies. Also thanks to the fairies, we can read with confidence knowing that nobody will get seriously injured.
My favorite chapter actually have relatively few fairy bits in it, instead it involves a humorous explanation to why ancient writings are the way they are. For anyone who has ever gotten stuck in a large meeting where there is no apparent progress, this volume is for you.
The author hasn't eliminated the possibility that there might be more side stories in the future. If that happens, this series would turn into something more like "Kino no Tabi", or perhaps "Guidebook of the World's Villages" as our heroine would name it. I am very happy to read this extra volume :)
Previous (2015-01-14): "Alice's Adventures in Wonderland" and "Through the Looking-Glass" by Lewis Carroll, illustrated by Kriss Sison
Next (2015-02-01): Walking Hoihoi-san