This drama is undoubtedly excellent, with its color palette being slightly dark unlike Imitation. If you've watched Imitation then you've probably seen that it's about a failed group who sticks close even through hardships but Idol : the coup is the complete opposite. It was very realistically portrayed, how hardships break relationships and how much hardships affect a relationship. Each of these characters have a past, some fears, and some hope. They all hope to be popular but the ways that they strive to achieve it is different.

CHARACTERS:
Our fl is somebody who can go to any extent to save the group, she can as she says "stoop low" but will make sure that the group is saved. She is like the backbone to the group but like everyone has limits, she has a point too at which she breaks down. But she believes that the group has hope.
On the other hand is Jihan, a member of a very popular boy band and the boy band is doing very well. But the problem with his character is that when he protects someone for whatever reason, everything else loses its importance. Now you may wonder why I'm saying that it's a problem. In this drama, it is a problem because when he starts protecting Cotton Candy, his own group goes at a risk and starts losing importance. It's difficult for Jihan to grip both of them together because Cotton Candy and MARS were never on speaking conditions.

RELATIONSHIPS:
Jenna-Jihan : I must say that initially, this relationship was completely one-sided, with Jihan giving everything and Jenna accepting, but later in the drama, Jenna also starts giving Jihan. They both understand each other very well because they share the same passion for music. If you're looking for a drama where the main characters understand each other and their relationship have very realistic ups and downs then this one is for you. [PS: I never lost hope in Jihan and I was right all along. :)]

Cotton Candy : They have a good friendship but like I mentioned hardships put a crack in their relationship with one member leaving and constant fights in the dorm.

Cotton Candy - Mars : Apart from it being a simple senior-junior relationship, they start developing empathy for each other. The quote to sum their entire journey is "Grass may seem greener on the other side but it isn't always". Cotton Candy was a failed group and they were unable to get any opportunities, it hurt them that they stayed in a booth for so long, practicing, giving their best to the company, only to get forgotten. They dreamt of being extremely popular. A member of Cotton Candy didn't even like MARS because she sorta blamed them. But MARS had its own difficulties. MARS being an extremely popular boy band subjects them to being very transparent; every action of theirs is always ensuring that their fans aren't upset. And it also subjects them to having rabid "fans", the kind who attack so frequently without understanding a situation.

All in all, this drama is excellent but it's not light hearted. It deals with alot of issues and the issue introduced in few eps might be triggering if you have experienced something like that. But otherwise, it deals well with all difficulties unpopular groups go through. They can neither get out nor stay in for too long. SO, yall watch this drama. It's damn good!