If you've heard of Oshi No Ko, currently streamable on HiDive, you've probably heard that it's a show about the realities of idol work in Japan (and likely in Korea as well as others, too.) And, to a degree, those descriptions aren't wholly inaccurate. But they're a little inaccurate.
Oshi No Ko is, in actuality, a slice-of-life/mystery anime that happens to feature characters in idol life and deals with the realities of that rather than with the pure excitement of trying to make it that you'll see in other shows. So, with a different focus, there are different parts of the story that get told or focused on.
Now, a lot of people who watch the show are going to be absolutely blown away by some of the stuff they learn. But a lot of other people - particularly those who either closely follow the industry rather than just stars, or those who have attempted to to professionalize their social media hobbies - will recognize a lot of the things the show goes into.
For example, at one point one of the characters admonishes two others for live-posting their location. She warns them that most idols don't do that because some well-meaning fans will show up demanding autographs and ruin their time but also they run the risk of stalkers showing up to cause problems, too. If you follow the industry or you've enjoyed even a moderate level of success on a platform such as Twitch, you're probably well aware of the dangers of stalkers.
But, again, the show isn't about those things, it just has those things in them as natural background to the characters. The show primarily stars two siblings, Ruby and Aquamarine Hoshino, born of a moderately famous idol, who both also want to get into idol work for their own reasons.
And, as far as a slice-of-life about idols goes, it's a pretty fun, low-stakes series with gorgeous animation and absolute bangers for the opening and ending. But before you can watch it, you need to know about the very first episode. It is as long as a dang movie and is almost entirely set up for the anime that I described for you above.
If you're anything like me, you'll quite happily judge an anime by its first episode and while the first episode of this anime isn't bad, it is also nothing like the rest of the series. Our protagonists don't show up until halfway through and even then, they're baby versions of themselves rather than the teens they become. Oh, and also, they're kind of "isekaied" into their bodies. So they're babies with the intelligence of much older people.
It's long and it's all set up for the series that comes after it so you might be tempted to skip it and just read a synopsis. I can't recommend against that enough. In fact, I just deleted most of my own synopsis because I think it's so important to watch the show the way it presents itself. it's true that a synopsis will tell you everything you need to understand factually, but there is so much emotion in this first episode that really prepares you for how you're going to feel about all of the characters and situations going forward.
You're going to be able to have a much better experience with the anime if you watch that first episode and live through those events with those characters. You should also prepare yourself for the fact that the stories told in that first episode aren't exactly happy, but even as a person who generally avoids sadness in their media consumption as a general rule, I must stress that, in this case, it's absolutely worth the payoffs you get as the show goes on. And I think it will be even more important as the story continues if it gets more seasons.
In short, please watch Oshi No Ko, but get ready for a long, tear-jerking opening act. You'll be glad you did.