I'm not 100% sure what you guys have in mind for the final release, so my bad if some of these are what you're already working on! Super fun game btw, I can't wait to play the released version :)
I know you guys are working on more relationship stuff between the idols and player, but I love drama and think it will really flesh out the game so here's some ideas:
-Idols gossipping about the group to the press or releasing secrets, either while in the group or after graduating. For example, if they're overworked and underpaid in the group, or if one certain member is known to be a bully, they might go gossip about it to the press after leaving. I feel that this is something that happens with idol groups in real life and will make the way you treat your idols extra important. Also it seems to me like the girls are basically irrelevant after they graduate, so it'd be cool if they still matter somewhat.
-More of a minor nitpick but they all seem to go onto pretty average things after graduating, like becoming an office worker or teacher. I think it'd add realism if their fame level impacts what they do after graduating. If an idol graduated with 10 star fame I'd imagine her to go on to become an actress, author, solo artist, etc. rather than have an office job or working at a hostess club. (My bad if this is already a thing, maybe I haven't graduated enough high-star idols to notice.)
-Events relating to the fame and safety of idols. For example, idols having stalkers, or being attacked by a fan at a fan meet. While it's sad, this is also something that has certainly happened in real life. It might cause an idol to have depression, or take a hiatus.
-I know a lot of people have mentioned this but having subgroups would be cool, or even solos.
-Maybe more tangible repercussions for idols being bad singers or dancers. An idol can have a singing and dancing level of 1 and she can reach 10 star fame and no one will say a thing about it. I think in real life, an idol would get made fun of if they were unskilled. Might be even worse if the entire group has poor singing and dancing skills.
-Idols leaving the group on bad terms. Certainly not everyone has a happy and peaceful graduation in real idol groups!
-I think it'd be nice to have more rewards in the late game. Maybe sending idols on a really nice vacation, buying them really nice houses, etc. I know this is just the beta so I'm sure I'm missing out on a lot but as of now once I have 1,000,000+ fans and a bunch of money in the bank, it's like, "Now what?"
Anyways I love this game and the beta is already addictive! Thank you guys for working hard on this game, I'm always looking forward to the next update.