After watching ep.1, I was on the fence about whether or not to continue. In the end, it turned out to be okay. It's nothing you'd recommend or rewatch, but I got through it without significant difficulties. It's quite likeable, in its unambitious way.
It's about idols. Hanako Yamadagi loves idols and has lots of natural talent, but unfortunately singing isn't one of them. She happens to see a C-list idol group (called Ongaku Shoujo) and falls in love with them, becoming their gofer, confidante and number one fan. Given the extreme modesty of their live event in ep.1, this might mean that Ongaku Shoujo have just increased their fanbase from 28 to 29. Can the girls survive in the cut-throat world of idols?
Answer: yes, obviously. The show isn't prioritising the industry's ruthlessness as much as the premise would suggest, instead being a generic rehash of all idol anime ever. There are eleven girls plus Hanako, which is too many. Does everyone even get a focus episode? They're amiable and nice, but sometimes a bit on the bland side. They also have a mildly anthropomorphic pet crayfish, which is where the anime tips over from "unremarkable" to "stupid cartoon". Fortunately it doesn't appear too often.
The writing can also be perfunctory. Crises will occur and then be forgotten about, for the sake of the next crisis. This means that none of them are threatening. Will Ongaku Shoujo be forced to disband? Will they manage to attract 10,000 fans to their live gig, as foolishly promised? Will SPOILER really quit the group? (The real shock for experienced genre fans would have been if someone hadn't declared that they were going to quit at the end of ep.10.)
That said, though, there are things I liked here.
Ep.6 is unexpected and fun. You'll see a mile off that the Meat Rival and the SPOILER are the same person, but what's fun is how it plays out. It's the silliness that makes it cool. ("The schoolgirl inside you!")
The industry's dark side is being softpedalled, but it's still here. Ep.5 has quite a memorable portrayal of a git with patronising, compartmentalised ideas of what idols can and should be. Ep.7's manufactured crisis is trivial and the girls' overreactions to it are annoying, but it's slightly shocking when the studio executives use it as an excuse to break up the group. (They know the story's an absurd fabrication, but they don't care. They're unhappy about it appearing in the newspapers in the first place, even though this kind of press attention is arguably proof that the girls have moved up in the world. No one would have bothered running stories about the group we saw in ep.1.)
The season finale also manages to be a bit different. Most idol shows don't have a non-idol protagonist, so seeing Hanako go out on stage is new and somewhat alarming. Suddenly you don't know what's going to happen.
This show is at the lower end of "okay". No more, no less. If you've never seen an idol anime before, don't start here. Try Love Live!, THE iDOLM@STER Cinderella Girls or Zombieland Saga (if you think that counts). This is an obviously cheaper, less intelligent show than those. It has episodes that I liked, but also others that struggled to hold my attention. (I was also sometimes irritated by the vapid TV game show they went on in ep.9, even though that's completely normal for the Japanese idol industry.) If challenged to cite characters without cheating and consulting the internet, I'd be able to pick out Hanako, the Ueno-Kiri sisters, the smug one with a cat smile and mischievous glasses and the one with no nudity taboo who loves eating meat. After that, I'd need to check my notes.
I mostly enjoyed it, though. I didn't hate the girls for being media vermin or anything. It's not pond scum, which is better than many idol shows.