It's two shows in one. The realistic, pretty grimy show is about the life of light novel authors. That's because the anime is based on a series of light novels by an author (Yomi Hirasaka) who'd had a rough time with his previous series, Boku wa Tomodachi ga Sukunai. His publisher made him keep writing the series even after he'd got sick of it, so he started sabotaging his own work by turning his characters into idiots and writing deliberately over-the-top plots. This series is what he did next. It's not a middle finger to the industry or anything, but it's certainly more cynical and self-mocking than, say, Eromanga-Sensei.
That's the show's heart. At the same time, though, it's also got a rampant deviant for a lead character and a not-very-convincing harem of girls who aren't repulsed by him. It's about light novels, but it is itself also a light novel series. Underneath, it conforms to the form. There's a male hero, potential love interests and a surprising amount of censored nudity that suggests lots of nipples in the Blu-ray version.
The good news, though, is that the show's take on the world of novelists is pretty good and well worth watching. The characters are bog-standard manga/anime fare (although ), but they're no more unconvincing than those you'll see anywhere else and I don't think they sabotage the show unless you want them to. I don't think the show's trying to be self-aware and make clever points, you see. Well, maybe the obvious one that "incest fantasies aren't a harmless cute kink but instead a way of making yourself scary-creepy"... and that hardly counts, because the show undercuts it by having girls fancy him anyway. I wouldn't call this show parodic. It's just that its subject matter makes it look as if it is. It's just writing with a lot of honesty about what it knows, except that on top of that is a layer of deviant characters and mildly horrifying sex comedy.
Our hero, Itsuki, has a little sister fetish. All his books have the hero's little sister as the romantic lead and they'll include lovingly written nudity. The first episode's first two minutes are actually his latest work (immediately rejected) and they're brilliantly, hilariously gross. Itsuki is an unrepentant pervert who's proud of his abnormalities and not particularly pleasant. He can even be appalling on a professional level, driving his editor to the point of criminal acts in his desperate attempts to make Itsuki finish this latest book before the real, actual, final deadline. (You're cheering for the editor.)
Other characters include:
(a) a girl with big boobs, Nayuta, who can only write her novels when naked and who's continually telling Itsuki to have sex with her. He rejected her two years ago, but she's never stopped being fixated on him and in all that time never even thought of moving on. Yeah, I know. You get a lot of those in anime.
(b) another girl with big boobs, Miyako, who's almost unique here in not being part of the book industry. She's just Itsuki's friend. She's a perfectly nice girl who's been hanging around him for even longer than Nayuta, which you may or may not find plausible.
(c) Haruto, a male author with a more pragmatic, calculating approach to novel-writing than Itsuki. He writes what he thinks will be successful. So far this seems to have worked better for him than Itsuki's approach. The good news, though, is that he's also a nice, modest guy who's easy to be around.
(d) Kenjirou, Itsuki's editor. The poor, poor man.
(e) Chihiro, Itsuki's step-brother who looks after him. Chihiro must be glad he's not a girl.
...and various other supporting characters, often also perverted. Ashley the tax accountant humiliates her clients by making them describe their adult video games and so on in lurid detail, ostensibly in the name of tax deductions. Kaiko the manga artist loves Itsuki's books and is moved by his sister complex, but complicates things with a fetish of her own. Ep.9 is magnificent in the appalling heights to which it takes perverts' impassioned disagreements over how to draw dirty manga.
The cast are fine, I think. The show's making no real effort made at writing their relationships with anywhere near the plausibility of its portrayal of the world of professional authors... but I don't mind that. They're normal for anime. This should only be a problem if you're expecting more than that, given the rest of the show. They're often quite funny, while Itsuki's ghastliness is brave and distinctive, up to the point where the show starts back-pedalling on it.
What's great about the show is simply its slice-of-life look at the world of authors. It shows us the games they play, e.g. storytelling card games. Ep.7 is all about an AD&D-like RPG, with goblins and magic. (Nayuta's input makes this the most censorable episode.) It shows us a range of professional attitudes, e.g. to their books, or to editors. It shows us the subtleties of breaking different kinds of deadlines, a bit like Eskimos having multiple words for snow. It shows us the sometimes strange mental places of an illustrator. It talks us through a writer's tax arrangements, which are surprisingly interesting. It shows us what it's like to have an anime or manga made from your work, not to mention the less glamorous flip side of never having had one. I loved all that. It's great. The series also makes it clear that many writers are lonely unsociable weirdos who couldn't cope with school and/or had a miserable childhood, each for their own reasons.
It's very good, I think. That said, it does have exploitative nudity-ridden sexual content and some pandering story elements. (If you analysed Nayuta's character on a realistic level, you'd probably decide that she was the most broken cast member of them all.) However I enjoyed it and I'd be happy to watch where Yomi Hirasaka took this series next.