This is easily the best volume so far. As a series, I've been a little iffy on this one. I haven't truly warmed up to the characters and it very much is a boy's coming of age but this volume started pulling all the threads together (and I have to wonder if this will be a relatively short series).
Taitou is finally coming into his powers and his responsibilities, even though it's making for tension between him and Laila (which I'm sort of hoping doesn't get shippy now that they know they're not actually brother and sister). They have to deal with Ryuukou's betrayal and his return as well.
As for his part, Ryuukou has done some things that cannot be undone and are close to unhinging him. In the meantime, Keirou has seized power and may, in fact, murder the emperor since he no longer needs him. This volume is taut and full of twists, including one I didn't see coming (and makes me think if you're a joker in anything Arakawa does, you may be in trouble). Big changes for everyone but especially Housei, Ryuukou and Taitou.
Black Butler #5 by Yana Toboso
As far as plots go, this one is much more simple than the last. Basically, Sebastian has to figure out a way to beat Agni's curry and win the challenge. He uses Soma as a taster (though why he didn't expect Soma to lie so Agni could win, I have no idea). Interestingly enough, Ciel rather wants Sebastian to lose.
Then comes the big curry contest and it ends as expected. For that matter, Soma's reunion with Mina (the reason he came to England) was also as expected. More interesting was Lau's reaction to all of this, darker than one might have expected.
The last chapter was probably the most interesting when Soma and Agni stay on in England and Agni, in spite of being warned, tries to turn himself over to justice. We get to learn a bit more about Ciel's staff and how very odd it is that before this they all had no one and nothing. There is portfolio art in front of one chapter of Soma that is amazing. That alone was worth the price of the book. This one was light and fluffy though after the last story arc that was probably needed.