I learned about IDOLiSH7 when checking out the recommendations beneath the "given" entry on Anilist. I truly enjoyed it and I wanted to watch something catching and affecting me like “given” did. But I did not know, since it wasn't even my intention to find a show that does so, that IDOLiSH7 will overwhelm me.

Of course, a story settling in show business can start fast and make the protagonists hit like a bomb. But, and this is the first of many parts this anime handles pleasingly, IDOLiSH7 starts rather slow and regular. The seven idol-mates-to-be play basketball & the inexperienced and suddenly crowned manager Tsumugi Takanashi, daughter of the president from Takanashi Productions, introduce each other individually. The first season is there to introduce the new members among themselves and with that also to the viewer. After some tough lessons, like a concert in front of only 9 viewers, they did not give up and strengthened each other.
The first season was pretty good, and some animes might have ended here. Watching it, I sometimes thought "I know why people rate it 10/10, but it’s not quite there now".
Now - not very far after, it became.

IDOLiSH7 is not just a happy Idol life with all the benefits, love, and fun, but also not a band that has to fight their way to the top, surrounded by all kinds of evil rivals.

The in-between it is makes it so perfect and realistic. It also leaves the viewer a big freedom in which bands and characters to like. No one (except maybe later - different story) is made to be the bad guy you have to dislike and who surely will fall after. Every character is unique and, like fellow review mate Amertsi mentioned in their review, you will find a character to relate to, maybe more than you thought. Everyone has a bag to carry, which they will face sooner or later.
Another point that makes the show outstanding is how long some stories take their time to complete. Something told alongside in season 1 might take action two seasons later - but completely natural and not forced.

Since this is an anime about Idols, the music plays a big part in it. And let me say you, the soundtrack is amazing. Since there are four competitive bands sooner or later in the series with individual styles, there will be songs you love listening to. Since I don’t want to anticipate who they are and what they sound like, it's best to just listen on your own, in the anime, and after that, completely. Since IDOLiSH7 began as a rhythm game, there are tracks not featured in the anime, which are also great, often with members of different bands or not the complete crew.

And with these words, if I could raise your interest just a bit, go watch IDOLiSH7 – if you like season 1, you’ll love the following seasons.