It's an idol anime that's a bit different. Okay, a lot different. Eight girls receive cards telling them to gather at a certain location, with no explanation. They're going to become idols together, including the shy wallflower who thinks idols are stupid and just shake their arses for the customers. This order has been delivered by the Wall, which is, literally, a wall. It's mute. It doesn't have a face or a body. It's a big underground wall that, every so often, rings scary bells and delivers gnomic orders via printed cards delivered through a slot.
These orders are absolute. You can't negotiate, because there's nothing to negotiate with. Your only two options are "obey" or "walk away". The Wall has a big minion (Gouda) who repeats this on every occasion, plus an army of henchmen who can organise concerts, TV appearances, tropical island trips, etc.
There are lots of idol anime, some of which are verminous. Those uncritically portray idols as wonderful, godlike and a glamorous aspiration for all girls. Some deconstruct this a bit and show some of the business's tougher sides, although I don't think any have yet gone so far as to portray, say, sexual exploitation by producers. (See for instance the 2018 court case with a former idol from Niji No Conquistador.) Probably the best idol anime, though, are the ones that get weird with it. Zombieland Saga is the greatest, but this show's on the "getting weird" list too. No one knows what the Wall is. Aliens? Time travellers? An idol-raising AI? No explanation seems likely, but it's undeniably surreal. (Actually, you could do something interesting with "time travellers".)
Oh, and why's it called 22/7? I assumed it was related to pi (for which that's a common approximation), but the show never says.
The show's doing interesting things with characterisation, usually involving inner contradictions. (Or, as Robert McKee calls them, dimensions.) Reika is nominated as the group's stern leader, laying down the law and brooking no nonsense, but ep.6 sees her ditching her responsibilities to the rest of the group. (Maybe. There's a discussion to be had there.) Jun is the group's irrepressible comedian, but ep.7 shows a shocking past. Miu is a wallflower who hates idols, but agrees to become one. Akane is the emotionless one who often gets called "robot" or "AI", but ep.8 shows the time before she shut off her emotions. These backstories can be harsh, including death, divorce and more death.
Similarly, the girls are initially unsuited to working together. For Miu it's torture, while Saitou has a sharp tongue and no patience with unprofessionalism.
In the Western fandom, ep.6 is controversial. Reika doesn't want to do a bikini photoshoot, but violating the Wall's orders might kill the entire 22/7 project. In real life, you'd have been 100% on Reika's side. The decision would have come from an ordinary person who was ignoring a teenager's personal boundaries. Here, though, I think the episode gets away with it. (Other viewers disagree, though, and real life comparisons are admittedly awkward. The timing's also unfortunate, since a 2020 show is very much the era of #MeToo.) In the 22/7 universe, though, you can't talk to the Wall. It's a non-negotiable zero-blame situation and no humans were involved. Meanwhile, the episode's a character study of someone who's serious to a fault and wouldn't normally forgive anything that could be portrayed as irresponsibility. And frankly, of course, the job's tame. Wearing swimsuits on a tropical beach with your friends isn't the worst thing in the world.
The girls aren't all equally memorable. Some are great (Miu, Jun, Kouno) and others you'd need to remind yourself about. You're happy to watch their focus episodes, but they fade into the background a bit. That was probably guaranteed to happen, but there are also story threads and potential relationship developments that never go anywhere. (Mostly all the gay.) Well, maybe we'll get a Season 2. I hope we do.
Incidentally, 22/7 is a multi-media project centred around a real idol group of the same name. It actually has 11 members, but only the first eight of them appear here (mostly). Its concept is "idols who transcend dimensions", using upcoming (i.e. cheap) voice actresses to play a fictional Japanese idol group both in animation (voice and motion capture) and real-life.
It's a good anime. It's interesting. It's an idol show where the girls didn't ask to become idols and don't work well together for a good third of the show. I like the characterisation, I like the strangeness of the Wall and I like the cast. It can be harsh, but having that weapon in its armoury is what makes it so much better than idol shows that are just candyfloss. It's nice.