Kannaduki no Miko (also romanized Kannazuki no Miko) is a pretty good 12-episode series, although it does take six or seven episodes to really get going. I would have given up on the show except it featured Ayako Kawasumi doing a serious, evil-sounding voice (which is always top notch), and I already saw spoilers about the later episodes which gave me hope that the show was going to get interesting later.
Kannaduki no Miko is about a love triangle with a lesbian slant. Souma (male) and Chikane (female) both love Himeko (female). The problem is Chikane and Himeko are the Moon Priestess and Solar Priestess, respectively, and Souma is one of the Orochi—one of the so-called "Eight Necks"—and is supposed to be trying to kill them instead of trying to screw one of them. Since Souma is in love with Himeko, he spends most of his time protecting Chikane and Himeko from the other seven Orochi. Protecting them with his GIANT ROBOT. Oh, I forgot to mention that part, didn't I?
Most of the time Souma, Chikane, and Himeko are high school students at an upscale academy. Souma is the "prince" of the school. He is handsome and athletic and popular and everyone assumes he's dating Chikane, the beautiful well-bred girl and undisputed queen of the campus—the girl everyone loves. Himeko, on the other hand, is just some blah, worthless, nothing of a girl.
It's not at all clear at the beginning why Chikane is in love with Himeko. Like I said, she's kinda worthless. Pretty much the only thing she has going for her is her genuine, unassuming, sincere nature. Everyone else we see in the school appears to be catty and coniving and mean. But c'mon, it's a big school. There has to be someone else decent on campus.
But Himeko is the Solar Priestess, while Chikane is the Moon Priestess. Chikane has to love her, because it's destiny and all that. It took me about eight episodes to fully accept this, though.
Oh, I was going to talk about the GIANT ROBOTS. Yes, apparently the world is in peril, and the Solar Priestess and the Moon Priestess have to save it by chanting. The Orochi try to kill them using giant, monstrous robots. Normally, this would be pretty easy to do, but Souma is in love with Himeko, turns traitor, and keeps the other seven Necks at bay. Let's ignore for now that Himeko is kinda worthless. Souma is in love with her, and that's that. Souma is also fortunate in that the Orochi are mostly content to go after our story's two helpless priestesses one at a time. They're pretty half-assed about it too, which is good for Souma, and good for Himeko, and good for Chikane, too, even though it royally pisses her off that she gets her ass bailed out of trouble by Souma all the time.
It's kinda hard to describe the other seven Necks. They form a rather absurd ensemble of caricatures including a manga artist, a pop idol, and a kid who alternates between acting like a cat and pursuing her obsession with administering medication. Most of the time they stand around bitching at each other until one of them goes and tries to kill Himeko and Chikane.
If Kannaduki no Miko sounds kinda mediocre right now, that's because it is—during the first half of the series. The second half of the series is pretty awesome, and is somewhat twisted.
The turning point of the series involves a substantial spoiler, so just stop reading if you're already at all interested in watching Kannaduki no Miko. Personally, I wouldn't have watched it all the way through if I didn't know all the spoilers already, but once I got past episode six or so, it got pretty captivating.
Being stuck in the losing corner of the love triangle, and constantly being rescued by the odious Souma, whom she loathes, and constantly being unable to protect her dear Himeko herself, Chikane snaps.
Yeah, Chikane kinda turns evil. Not SUPER evil, just kinda evil, and she already seemed kinda evil to begin with. And then she starts kicking ass wholesale.
I should probably mention the sexual assaults at some point. I'm too lazy to craft an adequate segue, so I'm just going to come right out and say that there are a few sexual assaults depicted in Kannaduki no Miko. They come in the "I'LL RAPE YOU UNTIL YOU LOVE ME" variety, the "Hey, do you wanna get ahead in this business or what?" variety, the "Shut up, I need this" variety, and also the "Oh, lighten up already, you know you could use a good fuck" variety.
I guess it all sounds kinda twisted, but that's mostly what makes Kannaduki no Miko so good once you get past the boring first half. Ayako's evil voice is always welcome, and everyone pretty much gets what's coming to them. so the payoff is good.
Plus it has KOTOKO singing the OP and ED. The ED, "Agony," is a particularly good way to end most of the episodes. It captures the thematic nuances of the show well.