Twelve-year-old Ciel Phantomhive is an orphan and a victim of a horrific past, but he is also a special agent of Queen Victoria, a head of industry (toys and sweets), and master of a palatial estate near London. Keeping house for the young master are a set of curiously and comically inept servants - Finnian the air-headed gardener, Mey-Rin the horrifically klutzy housemaid, Bardroy the lethally bad wise-ass cook, and Tanaka the (mostly) inert steward - plus Sebastian Michaelis, the super-efficient and multi-talented butler.
The charming yet steely Sebastian is, in fact, a demon from Hell. Literally.
This beautifully drawn series careens vertiginously from horror-tragedy to broad comedy. Ciel investigates Jack the Ripper, is befriended by a feckless South Asian princeling who gets the household involved in a very serious curry-cooking battle, and most recently delves into a strange circus that may be playing a role in the matter of some missing children. Flashbacks reveal the nature of Ciel's relationship with Sebastian, why Ciel has that eyepatch, and what happened to the rest of the Phantomhive family. And Queen Victoria is not the only 19th century celebrity to make an appearance.
To quote TVTropes, "Mix and stir Hellsing and Count Cain with Loveless, at least toward the beginning. No, seriously." The gorgeous illustrations always have a kinky air about them, a number of characters are motivated by various sorts of barely-bridled lust, and mangaka Toboso loves to cross-dress Ciel. Although the series runs in a shounen magazine, the slyly elegant sexuality running throughout is just one reason that this is not a series for kids of Ciel's age (Yen Press rates it as "Older Teen").
The series features yet another take on shinigami, who in this case are spiritual bureaucrats/investigators who have to collect and account for the souls of the recently departed. BB shinigami are always turned out in natty Victorian dress suits (black, except in the case of the flamboyant Grell), wear glasses, and are equipped with "death scythes" that can be just about anything in the outdoor tools department: a long-reach tree-pruning saw, a lawn mower, and a chain saw have all made appearances.
I have just finished Volume 8, which wraps up the Noah's Ark Circus arc. Frankly, I had to close the book for a moment and just breathe at one point. It wasn't so much the death and destruction. Although there was plenty of that, it was certainly no worse than scenes in many of the seinen series I've been following. It was more the emotional cruelty of the various situations: for the child performers of the circus who paid the ultimate price for their master's deeds (and some of whom learned, just before they died, what he had actually been doing) and for Ciel, who was in reality their executioner (although his servants did the killing) and who is prevented from performing the one act of mercy that he hoped would expiate some of his guilt.
Ciel and Sebastian remind me of what sanada told me at one point about Samurai Deeper Kyo: "In most series, these would be the villains." I certainly plan to keep reading Black Butler, but I'm a little disturbed by the type of enthusiasm I'm seeing from some of the fans. There are some very dark, deep currents running under the beautiful artwork and slapstick humor.