I liked ep.1 a lot. I had no idea where things were going. A six-year-old boy gets bitten by a vampire, who inserts her poison into him to ensure that he'll never leave her. Next, though, a high school boy wakes up from a dream. (In his classroom at school. Even the teacher hadn't been able to wake him.) The show has a real-world school setting, with a childhood friend (Haruka) and a staggeringly rude boy who's super-popular with all the girls. Oh, and panty shots. Then the episode turned upside-down again with the decapitation truck incident and... what the hell?
People get better impossibly and someone gets impaled. All this was great. Then, though, we started learning more about the show.
Our hero, Taitou, is willingly enslaved to an immortal-ish vampire girl (Himea) but also has a childhood friend who really likes him and will make him packed lunches he didn't request (Haruka). In other words, it's a love triangle, but a one-sided one because Taitou is completely Himea-focused and no one else in the world can get between them. What makes this uncomfortable is the fact that the two girls aren't bitchy about it. They're insecure and find each other's presence painful... and neither Taitou nor the show itself ever clears the situation up. I kept waiting for a frank discussion that wasn't happening.
Theoretically, that's unremarkable. You can see something similar in a million harem anime, but it's worse here because Taitou's clearly hurting both girls by not making things clear. There's a similar example of Piss Right Off judgement in ep.7 when Taitou visits a sinister extradimensional entity and makes a very, very inadvisable deal because he wants to be able to protect Himea.
Let's examine this. Taitou is a 15-year-old human boy, albeit boosted by Himea's magic. (He's slightly immortal.) Himea is 10,000 years old and either a vampire (despite eating human food and almost never showing any vampire traits), a witch or some other kind of creature that could destroy the world. Nonetheless, Taitou wants to be the one who protects Himea. Why? Because... uh, because you hear that a lot from male anime protagonists. It's more than a little absurd, but later we'll see the girls turned into kidnapped plot coupons while the boys become their heroic rescuers.
Taitou's school is at the intersection of multidimensional rifts that can't be used by anyone over the age of 18. (Unless, uh, you're a 10,000-year-old vampire. But let's not focus on that.) Members of the school council are excused from attending classes, which outrages me. Why does Himea never attend classes, even though she's transferred in to be a student? The show's portrayal of this school is barely even pretending to be a school. Similarly, the president (Gekkou) is a cock and it's delightful to see him taken down a peg when that teacher shows up. Yes, I realise that Gekkou's actually nicer than he seems, but he's so abusive that I don't care. There's also a military organisation that operates above the national level and has authority exceeding the police, the JSDF and even the government.
The show has unattractive fanservice. The art style makes the boys much prettier than the girls, but there are blatant panty shots and occasional nudity-fests. (Including ep.9's closing credits and the public baths in ep.12.)
Reviewers weren't kind to this anime. I don't care about some of the reasons why (one-sided fight sequences, excessive name callouts, plot changes, etc.) but I'm not keen on the show either. It's at its worst when its interesting ideas collide with genre formulae and old-fashioned gender roles that don't fit it. It's based on a light novel series and it doesn't even resolve itself properly, ending on a cliffhanger that was probably set-up for a Season 2 that never happened.
Avoid this one. You can do much better.