It's a Pink Pineapple hentai from a game by ELF. It starts horribly. A naked woman's being tortured with electric shocks by someone who wants her as his slave. I was on the point of quitting... but then the real story began.

"In my summer vacation before my last year of college, I joined a mystery tour. One day, my friend Seigu Takashi was sent free tickets for it. You won't know the destination until you get there, etc. I usually ignore this kind of stuff, but this time was different. It felt as if something was calling me."

Mismatched holidaymakers are on a cruise ship. The protagonist is Sudou Ryuuichi. (A bit of a pervert, but a nice guy.) This friend Seiguu Takashi is with him, of course, as is Ryuuichi's childhood friend Wakaba. She insisted on coming. (They must be the same age, but she looks like a child and is barely half his height.) The only other young people are two girls: Suzuki Hiromi (hostile to men) and Inagi Shouko (has a shy crush on Takashi). As for the older passengers, they're disturbing. Shinohara Yuuji is a smug, fat lech who gropes his possibly masochistic wife Tomoko in public, watched by a big, seething man called Ito.

None of these people know their destination, which is a post-apocalyptic wasteland. Dangerously decrepit buildings and no plant life. "Oka Island became deserted about eight years ago because of the closure of the coal mines. This tour was planned by the current owner of the island, Mr Okouchi, and he invited people who used to live here to remember the old days. It's a short trip, but he hopes you enjoy your stay."

Spoiler: no chance of that. This story is scary and disturbing. Bad things will happen, usually involving bondage. You can tell what fetish this anime's targeting, but the results are anti-erotic for everyone else. Only one sex scene in this hentai doesn't involve bondage and/or masochism and that's near the end of the last episode. I don't think the show's even aiming for "sexy", but instead "unsettled and distressed". Remember that woman who was being tortured? She gets killed and frozen in liquid nitrogen. Mr Okouchi is a psychopath with both a stun gun and an ordinary-bullets gun, to be used on people who don't want to become his sex slaves. (Or, indeed, people who do. He's indiscriminate.) Hiromi, Shouko and Tomoko all have issues. This story's cast can be divided into three categories, with overlap between (a) and (b):

...and yet the show's quite good. It's so anti-arousing that it plays like a slow-paced horror, not hentai (and there aren't many hentai scenes anyway). I liked our heroes and their slow, methodical exploration of their environment. The characterisation is on the dark side, but that fits. Sometimes it's shocking.

The only problem is the art and animation. I'd hoped for better from Pink Pineapple. Okouchi looks cartoonish enough that it's sometimes hard to take him seriously.

The finale goes supernatural, which might annoy some viewers... but I liked it. It was foreshadowed from the beginning, including the title. "Hyakki" means "100 demons", c.f. the Night Parade of One Hundred Demons ("Hyakki Yagyou") that's a Japanese equivalent of the Wild Hunt or Walpurgisnacht. What happens at the end is what our heroes have been trying to achieve since ep.1. Secondly, it gives this black, black story a happy ending. (Don't miss the post-credits sequence, unless you want to stop on the depressing first ending.)

I'm not convinced that Okouchi's dead, though. If they made a sequel, he'd return. If I were Ryuuichi, I'd go looking for Okouchi's body, sever his head and bury him at a crossroads with a stake through his heart.

If you're into horror, consider this. Just don't watch it in public, or with anyone who's sensitive to art quality. It's suspenseful, disturbing and emotional.