Tooth and Claw, by Jo Walton
It's a Regency romance novel with cannibalism! The characters are all dragons, who eat each other:
He's expected to eat her when she dies naturally, see. There'll be troubling social repercussions if he doesn't wait that long - he'll probably have to rusticate for a season or two.
Also, when female dragons lose their virginity, they turn pink, and if they turn pink before they're married they are Fallen Dragons and cast out of their homes, and other dragons can eat them with impunity. The children of the poor are also eaten pretty much whenever by the upper classes, as are elderly servants, and their wings are often bound to keep them from flying. The more other dragons you eat, the bigger you get, so that dragons of the upper classes are the only ones who regularly grow longer than seven feet, making it easier for them to dominate the lower class dragons, and by the way are these metaphors clear enough.
Yet it's not an obtrusively didactic book. The cannibalism and turning pink is gracefully established the rules in the first couple chapters, without any special emphasis, and Walton follows them precisely throughout the book - but none of this actually changes the character of the Regency era as-seen-in-romance-novels much. It just reads like a Georgette Heyer novel. It's appropriate to call it satire, but it's that sneaky kind of satire that can just as easily be enjoyed as an example of the medium it's poking holes in.
Superior v 1-9, by Ichtys
The hero Eksa has been sent to destroy the Demon Queen Shira, with whose forces the humans are at war. Shira sees him coming, and on her second-in-command's advice decides to spy on him a little to ascertain his weaknesses before trying to kill him. She does this pretending to be a weak demon-in-distress who needs his protection. This works pretty well on Eksa, who actually wants to make peace with the demons, and hates killing.
Though the Demon Queen finds this idea baffling and contemptible, she against her will falls in love with him in chapter one. Her thinking on this is basically, "Darn it, this is going to make it hard to kill the guy... Oh, well." Still hiding her identity from him, she goes off and has adventures with him, Shira struggling with alien human ideas like "you can't eat everyone you don't like" and Eksa anxiously trying to make peace between the demons and the humans.
Because all fantasy-manga adventurer parties should consist of four people, I guess, they shortly acquire a womanizing swordsman guy and a short-tempered magician girl. Because all fantasy-manga adventurer parties require a Boss Fight to look forward to at some point in the future, Shira makes a golem that looks like herself to take her place while she stays with Eksa, and the golem turns on her, declaring itself the true Demon Queen. Its name is apparently just Copy, though. It should change that.
It's honestly pretty stupid; though it starts as comedy, there are volume-long collapses into limpid angst. Most of it is a pattern of Stupid Pratfall, Stupid Angsty Fight Scene, People Express Inane Ideas About War While Weeping For Like The Whole Chapter. All kinds of sparkly shoujo tears; the whole cast does it.
But I finished it up because Shira does stuff like this:

I find this refreshing in a shounen manga heroine. It ends at volume nine in the middle of a plotline, but there's a sequel series called Superior Cross, which I may go ahead and read.
I've decided to start grading translations, by the way; as you may have guessed from the panels above, none of the various scanlation groups that have worked on this get more than a C from me.
(Hoshin Engi is in same situation, and I include the regrettable official Viz translation in this judgment. I seem to recall that some scanlation project working about eight years ago did a decent job on the first few volumes, but I can't find those particular scans now.)
It's a Regency romance novel with cannibalism! The characters are all dragons, who eat each other:
"You wouldn't dare," she said. "To be known as the Exalted Lord who ate his mother when she was strong and well?"
He's expected to eat her when she dies naturally, see. There'll be troubling social repercussions if he doesn't wait that long - he'll probably have to rusticate for a season or two.
Also, when female dragons lose their virginity, they turn pink, and if they turn pink before they're married they are Fallen Dragons and cast out of their homes, and other dragons can eat them with impunity. The children of the poor are also eaten pretty much whenever by the upper classes, as are elderly servants, and their wings are often bound to keep them from flying. The more other dragons you eat, the bigger you get, so that dragons of the upper classes are the only ones who regularly grow longer than seven feet, making it easier for them to dominate the lower class dragons, and by the way are these metaphors clear enough.
Yet it's not an obtrusively didactic book. The cannibalism and turning pink is gracefully established the rules in the first couple chapters, without any special emphasis, and Walton follows them precisely throughout the book - but none of this actually changes the character of the Regency era as-seen-in-romance-novels much. It just reads like a Georgette Heyer novel. It's appropriate to call it satire, but it's that sneaky kind of satire that can just as easily be enjoyed as an example of the medium it's poking holes in.
Superior v 1-9, by Ichtys
The hero Eksa has been sent to destroy the Demon Queen Shira, with whose forces the humans are at war. Shira sees him coming, and on her second-in-command's advice decides to spy on him a little to ascertain his weaknesses before trying to kill him. She does this pretending to be a weak demon-in-distress who needs his protection. This works pretty well on Eksa, who actually wants to make peace with the demons, and hates killing.
Though the Demon Queen finds this idea baffling and contemptible, she against her will falls in love with him in chapter one. Her thinking on this is basically, "Darn it, this is going to make it hard to kill the guy... Oh, well." Still hiding her identity from him, she goes off and has adventures with him, Shira struggling with alien human ideas like "you can't eat everyone you don't like" and Eksa anxiously trying to make peace between the demons and the humans.
Because all fantasy-manga adventurer parties should consist of four people, I guess, they shortly acquire a womanizing swordsman guy and a short-tempered magician girl. Because all fantasy-manga adventurer parties require a Boss Fight to look forward to at some point in the future, Shira makes a golem that looks like herself to take her place while she stays with Eksa, and the golem turns on her, declaring itself the true Demon Queen. Its name is apparently just Copy, though. It should change that.
It's honestly pretty stupid; though it starts as comedy, there are volume-long collapses into limpid angst. Most of it is a pattern of Stupid Pratfall, Stupid Angsty Fight Scene, People Express Inane Ideas About War While Weeping For Like The Whole Chapter. All kinds of sparkly shoujo tears; the whole cast does it.
But I finished it up because Shira does stuff like this:

I find this refreshing in a shounen manga heroine. It ends at volume nine in the middle of a plotline, but there's a sequel series called Superior Cross, which I may go ahead and read.
I've decided to start grading translations, by the way; as you may have guessed from the panels above, none of the various scanlation groups that have worked on this get more than a C from me.
(Hoshin Engi is in same situation, and I include the regrettable official Viz translation in this judgment. I seem to recall that some scanlation project working about eight years ago did a decent job on the first few volumes, but I can't find those particular scans now.)