It's the first new volume of Yotsuba &! in over two years! It was published in Japan in November 2015. Kiyohiko Azuma doesn't work very fast these days, although he hasn't actually stopped. There have been two more Yotsuba &! chapters in Dengeki Daioh since then, presumably one day to appear in a 14th tankoubon, although on current form I'd expect that in 2018.
This is my fourth Yotsuba &! review, so I'll try to be brief. Yotsuba is a tiny green-haired girl who lives with her adoptive father and does mildly demented Small Child Stuff that might drive you mad if you lived next door. That's it. That's all the plot you're getting. It's lovely. Azuma's been working on it so far for thirteen years, thirteen volumes and thirteen million copies sold worldwide, winning awards and getting on bestseller lists.
Everyone in Japan says Azuma's losing it a bit here as an artist, mind you. He's turning out his pages so slowly that he's getting out of practice and the regular cast are drifting off-model. Tomoko demonstrated this to me by comparing the book with earlier volumes, but to be honest I wouldn't have noticed on my own and I didn't have a problem with it. Once or twice, maybe, it registered. Overall it looked fine. That said, though, I did notice that Azuma temporarily writes out most of the regular cast, which might have incidentally served as artistic self-defence. Characters can't go off-model if you're not drawing them! Instead, we have Granny. Yotsuba's granny comes to visit! (That's not her real granny, of course, since not even Yotsuba knows who her real relatives are. I'm still unclear on how Daddy managed to smuggle Yotsuba into the country and persuade the Japanese immigration authorities that he was the legal guardian of this random urchin.)
Anyway, Granny's the most important supporting character in this volume. However we do meet all three Ayase sisters, plus Yanda (ch.90) and of course Daddy throughout. Granny's the guest star, though. She completely crowds out second-string supporting characters like Jumbo, Miura, Torako or Shimauu.
How's the book, then? Is it great? Nope. Is it good? Obviously, yes. However it's fairly average by Azuma's standards and for me there were only two chapters that get up to the brilliance of his strongest work. The first is ch.86 ("Yotsuba & Souvenirs"), which showcases her joy at the arrival of a brusque, slightly scary man-woman and the magnificently tactless way Yotsuba focuses on the important things in life, i.e. presents for Yotsuba. After that, the second is the short and epilogue-like ch.90, ("Yotsuba & One Day"), which ends with Daddy and Yotsuba going berserk with mock fantasy battles and childishness. There are things to criticise in Daddy, but he's also kind of amazing.
It's interesting to see how Yotsuba herself has changed over the years. (Is it intentional?) She's got brattier in recent volumes. She'll act up more when things don't go her way. She's also lost that total ignorance she had in the early volumes, when pretty much everything was something she'd never experienced before. Going out in the rain, for instance. That was new for her. Back then, she hadn't even been in Japan for long. She'll also say hilariously appalling things without the faintest idea that anyone might get offended, but that hasn't really changed.
Speaking personally, having a child who's approaching Yotsuba's age has made me appreciate even more how well-observed it is. They way you'll get used as furniture, for instance. Azuma has a knack for letting scenes unfold in a natural, unforced way that feels more authentically inhabited than most manga or comics. I particularly like his use of dialogue-free panels.
Bizarre fact: there's going to be an anime spin-off! It's to be inspired by a cardboard robot costume that Ena and Miura made in ch.28, but taking it literally and telling the story of a race of cardboard box-shaped alien cats. It's called Nyanbo! and it'll be in five-minute episodes from October 2016.
In short, it's good. It's Yotsuba &!, so that goes without saying. I liked it. I'd defend the art too, which I think is fine and certainly much less cartoonish than, say, the first three volumes. (Azuma himself doesn't like looking back at those, although I think he's being far too hard on himself.) However this series has often been hysterical and one of the best things ever, which I don't think is true of this volume. I believe Azuma's slowed down in recent years partly because the flow isn't coming as naturally as it used to. He says he's finding it harder to come up with the ideas. This would have been a satisfying conclusion to the series, as it happens, but I'm very happy to learn that he hasn't stopped yet and that one day I'll have vol.14 in my bookshelves too.