It's pretty weird, a little bit dark and reasonably cool. I quite enjoyed it. I'm looking forward to Season 2.
It's set in a sort of timewarped Japan that has mobile phones, computers, etc. but also lots of long-dead famous writers who are alive again, with superpowers. They dress as if it's still the 1920s or whatever. These writers tend to group together into organisations. There's the Armed Detective Agency (sort of approximately nice-ish, sometimes), Port Mafia (mass-murdering gangsters) and The Guild (Americans, eeeeek). Americans might be worse than Mafia, but fortunately we only meet them in ep.12. I bet they're back in Season 2, though.
Our hero is Atsushi Nakajima, who can be annoying. He's an orphan with self-esteem issues that border on self-loathing. 'How severe?' I hear you ask. Well, in ep.8, he has the following realisation. "If I saved those people's lives, would that mean it was okay for me to live?" He's liable to make serious mistakes based on his own assumed worthlessness, or even be on the point of doing bad things. He'll try your patience. However he's also a nice guy who's capable of doing what he does in ep.8, which means I'm basically on his side no matter what.
He ends up with the Armed Detective Agency. Let's call them the good guys. They're fighting Port Mafia, anyway. They're a bunch of misfits, clowns and freaks who do occasional detective jobs and aren't overly burdened by morality. There are also nearly a dozen of them, so they're split into core members (appearing in most episodes) and fringe members (who might get a spotlight episode). These include:
OSAMU DAZAI - flippant layabout and flirt who takes nothing seriously and is always trying to commit suicide, but is always cheerful anyway. He's one of the happiest people in the show. He's funny, awesome and an appalling person, although you might find him in bad taste since the real-life Osamu Dazai (1909-1948) eventually succeeded in one of his many suicide attempts.
DOPPO KUNKIDA - Dazai's irritable partner, whose superpower lets him summon things into existence by drawing them in his notebook.
RANPO EDOGAWA (spotlight ep.5) - brilliant detective, but also childish, lazy, self-centred and in need of endless praise from the lesser mortals he's so condescending to. (The real Edogawa Ranpo (1894-1985) might be the best-known internationally of these Japanese authors.)
KENJI MIYAZAWA (spotlight ep.11) - pure gold. He's a happy, sunny yokel who doesn't understand complicated city things like money. He also believes everything he's told and will ask a bunch of obviously guilty gangsters to their faces if they committed a murder he's investigating. Going on a case with Kenji might take years off your life. (The real Miyazawa (1896-1933)'s works include Night on the Galactic Railroad.)
AKIKO YOSANO (spotlight ep.8) - she's unkillable and can heal any mortal wound, including other people's. She's the agency's medic. She can't heal you if your wounds aren't mortal, but fortunately she can solve that problem. Just inflict some! Everyone in the agency is terrified of her.
JUNICHIROU AND NAOMI TANIZAKI - in case you thought anime didn't have enough suggested incest. (They're barely in the show, though, and apparently it's also a literary reference to the real Tanizaki's works.)
The Armed Detective Agency aren't always virtuous, but at least they don't leave piles of machine-gunned corpses. So that's better than Port Mafia, then.
Do you need to know anything about Japanese literature to watch this anime? Nope. In fact, a little knowledge might actually be a hindrance. I didn't understand Akutagawa's power, for instance. Why Rashoumon? It didn't seem to fit. I've since looked it up and discovered that, yes, the real Akutagawa did indeed write the short story that the Akira Kurosawa film comes from, but in fact the plot similarities are scant and Kurosawa's film is instead based on a different Akutagawa story ('In a Grove'). That makes more sense now.
Is this show an all-time favourite? Nope. It's pretty good. Nothing wrong with that. Its episodes go from "perfectly okay" to "good", with a few that are excellent. Atsushi's prone to being pathetic, but I'm cheering for him anyway because of Kyouka. Besides, I'm quite looking forward to the Guild bringing in some English-language authors I actually know about. Happy to keep watching.