Whoah. More disturbing than any other horror anime I've seen. (Something like Rin - Daughters of Mnemosyne
is going just as hard for the gag reflex, but can't match this for sheer density of themes and offensive content.) Ep.6 came close to grossing out even me, while ep.8 is hardly a stroll in the park either. The manga's fans have trashed it hysterically and I'm sure it's a travesty if judged as an adaptation, but as a work in its own right I think it's actually quite interesting.
It's that four-minute episode run time. That's not four minutes of story, by the way, since it includes thirty seconds of opening credits and another fifteen at the end. To say that this series has a storyline would be generous. It's inherited the pieces of one from the manga, mind you. They're all there, but reduced to a series of vignettes that happen in asynchronous order and combine into a sort of thematically linked mosaic. There's plot-like progression. There are villains, arguably even too many. Lots of plot-like stuff happens, most of it disgusting. (Have you ever seen cannibalism used as an incest metaphor? If not, here's your chance!) However the series doesn't really coalesce into a dramatic narrative, especially if you take the non-ending into account.
Instead it's just a bunch of fragmented episodes, but I enjoyed that. Disorientation and alienation can be very effective horror tools. We often glimpse things instead of seeing them directly, e.g. Yume and Utsutsu's parents. We never meet them. (Apparently that's not true in the manga.) However they're still powerful presences, looming over the anime like spectres. Dad was a child abuser (violent, not sexual) and wife-beater who gave Utsutsu his interesting scar collection. At least he's a straightforward monster, though, whereas his beaten wife's story is disturbing.
The main characters are a brother (Utsutsu) and sister (Yume). They love each other. Yume's innocent and gentle, which suggests that she doesn't remember much about her parents. (Yume and Utsutsu have been effectively orphans for ten years.)
One day, Yume is told to beware of the red butterflies. She doesn't. When they come along, she (rightly) thinks they're beautiful. This is a mistake and she suffers the standard punishment for the crime of seeing red butterflies, viz. to turn into a demon who'll uncontrollably kill and eat anyone nearby. (And I do mean anyone.) Admittedly this only happens when she's hungry, but she seems to be hungry all the time. What's worse still is that in her heart, the poor girl's still the same good-natured innocent, devoted to her brother even when disembowelling him and swallowing his entrails.
Yume doesn't want to be a monster, but unfortunately human flesh is just too delicious.
You'll have noticed that Utsutsu gets killed, but don't worry. He gets better. His sister's condition is infectious, so now we have two monsters. Utsutsu's sworn to protect Yume, including from herself, so the two of them come up with an interesting way to stop her from going on murder sprees. Monster-Utsutsu can regenerate bodily damage, so why not let Yume repeatedly eat her brother? This is shot imtimately, made to look almost indistinguishable from sex while still being a scene of someone biting off and eating lumps of flesh from her half-naked brother's body. (All the time, she's saying/thinking "big brother, big brother, big brother".) I think we can call this "forbidden love". It's partly censored in the TV version I watched (white and black bars across the screen), but that just makes it look all the more horrific and sexual.
The incest angle then gets taken to another level when Maria (a motherly but psychopathic scientist with no ethical boundaries whatsoever) orders that one of Yume's eggs be fertilised with Utsutsu's sperm.
You get the idea. It's luridly horrible, i.e. great. However it doesn't make much literal sense, perhaps better viewed as a thematic exploration than as a story with internal reality. If this is infectious, why doesn't it infect Yume's other victims? What about Utsutsu's victims? Isn't he killing and eating too, then? (If so, we don't see it.) How does the alternate monster origin of ep.5 fit in, especially since the suggestion of that episode is that Utsutsu and Yume are biologically different and so the latter's monster-fication shouldn't have anything to do with Utsutsu? What's the story behind that conception anyway? (I know the answer because I've just looked up what happens in the manga, but there's nothing about it in the anime.)
Besides, might the monster-fication perhaps be better viewed as a literal expression of our heroes' inner demons? Utsutsu might still be carrying some of his father in him, while Yume might be carrying some of her mother. That could screw up anyone. Maybe it's a manifestation of insecurity, fear, anger and/or unhealthy mutual dependence between two siblings who make declarations of eternal love and say things like "I'll never let her go".
The ending is hard to get behind, though. Ep.11 doesn't really take the story anywhere, but at least feels vaguely conclusion-shaped. Our heroes have found a sort of status quo. (The manga, on the other hand, most definitely has an ending.) However ep.12 then does a kiddie flashback with little Utsutsu trying to get a replacement teddy bear for little Yume. We're introduced to their friend Arita and his three sisters. There's no horror. No one gets killed or eaten. The end. What? It feels like the first episode of a non-existent season two, easing us back in with pointless fluff.
That said, though, I'd point out that teddy bears are a big thing in this show. They're a motif. The abuse and wife-beating in ep.1 is portrayed in cuddly metaphor with bears. Yume owns a teddy bear that in her imagination will talk and even grow fangs. Our heroes' teddy bears represent childhood and humanity. Thus I think it's more meaningful than it looks to have kiddie-Utsutsu trying and failing to win kiddie-Yume the biggest teddy bear they've ever seen.
For a general audience, though, ep.12 will be exasperating. It's part of why everyone calls this a bad show.
It's not for everyone, to put it mildly. If you're not a horror fan, don't bother. It's an equal-opportunity offender, nearly guaranteed to drive away normal people while also annoying the manga's fans. The running time doesn't allow much space for characterisation or creating a narrative. (The former I think it achieves, though, not through either Yume or Utsutsu on their own, but through the relationship between them.) Personally, though, I found it really interesting. It's like a distillation of itself. Judged solely by the narrow criteria of how well it works as horror, I think it's fantastically successful.
"That's why I love pain. It's how I know I'm living in reality."