It's set in the immediate afterlife, when the dead get judged. An emotionless bartender (Decim) and a black-haired girl greet the deceased and make them play games, in order to expose the darkness in their souls. Darts, billiards, card games, etc. Could be anything. Doesn't matter much. What's important isn't the game itself, but instead the players' secrets and increasingly desperate attempts to save themselves. (The death games are only only used to judge pairs of dead people, who must have died at the same time and often together.)
Next: either reincarnation or oblivion. And yes, any given character is just as likely to meet either fate.
It's a unique premise. Some might even call it gimmicky, but fortunately the low episode count, a lot of variety in the Deceased of the Week stories and a slow-burning background story keep it from getting repetitive. There's quite a lot of staff in the afterlife. Decim has a boss and colleagues, some of whom run other bars and judge the dead.
Sometimes it's an anthology show. It shows us two characters and asks whether or not they deserve oblivion. This can get pretty dark, although fortunately on balance this is a sympathetic, humanist show. At other times, though, it's exploring the effect of all this upon our regulars, even though most of them claim to be immortal and emotionless. This is rubbish. Look at Ginti. Is he emotionless? One of the key things about this setup is how unreliable and fallible it is, including the horrifying notion that there will be a judgement after we die... but that our immortal judges aren't guaranteed to get it right. They're not human. They don't understand us, really. So you made a mistake, Decim? Whoops. Well, it's too late now to get her back from the void of oblivion. Don't worry; happens to all of us. Better luck next time, eh?
Other arbiters can be sadistic gloating bastards. Oh, and their methods are deeply questionable (and will indeed get questioned).
Personally I found this fallibility hard to get past my instincts. When one sees a supernatural immortal judging the dead and what kind of afterlife they'll be sent to, one wants to trust that judgement. Each episode is obviously about its characters' ultimate fate, but you may or may not be able to bring yourself to ask the subtler question of whether that decision was the right one.
Then there's the question of what exactly those fates are. The players are told that it's Heaven vs. Hell. This is apparently a lie and it's really the void vs. reincarnation, but what exactly is the void? Is it non-existence, or is it more like Hell as Ginti says in ep.11? He's probably lying, though. These people lie all the time. Even those masks (Buddha mask vs. demon) might conceivably not mean what you'd think, since the Black-Haired Woman in ep.0 asks about the players' fates even though the masks were visible above the elevators.
(There's some background behind that ep.0, by the way. This series is the sequel to an episode-length short film, Death Billiards, that was produced for the Young Animator Training Project's Anime Mirai 2013. The Japanese government's been sponsoring this industry training programme since 2010 and to date the only two short films to have got a spin-off are both from 2013. The other one's Little Witch Academia.)
After finishing the show, I was impressed but a bit confused. I didn't feel I'd got a handle on what the show was trying to say. We see and learn so little. What kind of afterlife do these people go on to? Is it Buddhist (i.e. the void would be nirvana and reincarnation the punishment)? That would seem unlikely, but we don't know. What's the show aiming for with this tale of death and the meaning of existence? That's clearly what it's about, at least in the most straightforward literal sense, but it's also wrapping itself in delicate, elegaic ambiguity and avoiding clear statements and messages. The central thread of Decim and the Black-Haired Girl is about the anti-romantic relationship between a near-robot and an amnesiac. The show keeps saying very final goodbyes to people, then it's as if they'd never been there and un-life goes on. Decim tries, mind you. He keeps his dummies, but even he doesn't remember.
Or does he? I don't know.
It's still delicate and haunting, though, if also sometimes horrifying. It feels like a show that would speak to you if you were coping with bereavement. It's dealing with moving on and saying goodbye to one's loved ones (or, fatally, not). It's including darker material like the psychological wake of suicide and the terrible things that people do.
What's it's not, though, is boring and arty. I blasted through the show at top speed. It's entertaining! The opening titles are funky awesome. The death games themselves are a laugh. Death Twister! And then there's the mightiness of ep.6, starring my heroine, Mayu. She is hilarious. She's trashy, shameless and a scream. She made me laugh pretty much non-stop. You can just watch ep.6 on its own and enjoy it, but I think you'd want to have watched all the preceding episodes to see what a hurricane of fresh air she is. After seeing good, bad and terrible people all being tortured by the worst things they ever did before possibly being wiped from existence, Mayu doesn't care about any of that and is just squeeing over her favourite pop star.
The more I think about this show, the more I admire it. I'm not sure I'd call it a crowd-pleaser, mind you. It has a minor-key ending that I imagine a general audience might find unsatisfying. It's doing none of the things that normally happen at the end of stories. Personally, though, I think I'm going to be mulling this one over for quite a long time. Years, quite possibly.