It's an anime comedy about fans talking about anime. It's quite clever and gets a bit meta, but eventually you can't call the earlier episodes "meta" any more because the ending's gone berserk and is eating the world. That's one freaky ending. I admire it, but I'd need more time to process it.
The show's quite good, I think.
It's a spin-off of a one-off short called Anime-Gatari. It aired in cinemas as an intermission thing, but then it went to series. This is that series. Our heroes include:
1. MAYA - the girl who isn't an anime fan in ep.1 and so will need everything explained to her. In other words, she's the audience. Even if you thought you knew anime inside-out, you will be Maya. This show knows and loves anime more than me, you and anyone I know. It's educational. It's full of titbits I didn't know and tweaked-name references to specific shows.
2. ARISU - the rich girl who spends insane amounts of money on merchandise.
3. MIKO - the bookworm. She'll have read the light novels before they got turned into anime and she'll bitch about the latter for cutting the best scenes and ruining the pacing. Naturally this tends to mean war with her fellow club members, who don't read books and don't care about the source material. Later, when the anime club make their own anime for the school culture festival, she'll be the long-suffering scriptwriter.
4. KAI-KAI - the massive ham and chuunibyou.
5. AURORA - serene, smiley, doesn't like his name.
Oh, and there's also a talking cat. No one gives him much thought.
Anyone who already knows everything we're told in this show is probably already an anime director. Ep.3 does cosplay, Akihabara and the three-episode rule. Ep.6 makes jokes about "god rays", i.e. those light beams that hide censorable things and will be mysteriously absent if you buy the Blu-rays. Ep.9 does sports anime. It's great because they know what they're talking about and the things they're saying are all true. When the anime club make their own anime, the show even starts lampooning the anime production process, with for instance Erika turning into the archetypal producer, who'll perpetrate outrages left, right and centre while sweet-talking her crew into not quitting and accepting it.
There are enemies. The school's student council is evil, persecuting the anime club because... well, to be honest, I initially assumed that this was basically a device to give the show something to do beyond having conversations. Oh, and Fat Teacher is capable of having a bit of a Fat Voice, which could be annoying.
Then, finally, comes the ending. It surprised me, even though I thought I'd heard all about it from spoilers. It goes meta in a way I don't remember seeing before, but then keeps going and turns that into the plot. In short, it's mental and if you watch this show with a friend, afterwards you'll be having conversations that go "what the hell happened there?" and "I thought the show had shut down early in ep.11, so I couldn't process what I was watching when the plot kept continuing." This ending will make your head explode and afterwards you should probably take some time to remember the earlier episodes, since otherwise the sheer loopiness of that ending might obliterate your memories of them. Those episodes were easier to process and hence, to be honest, probably more enjoyable.
This is a gloriously clever show, but most people probably won't see and/or care about its cleverness. It's just talking about anime. That's what the title means in Japanese. It doesn't have much of a plot almost until the ending (which is bonkers) and you probably won't enjoy the show if you're not already interested in the subject matter. I wouldn't recommend trying to marathon it, even for its fans. It's interesting, though, and I found it funny.