Well, I guess the idol tag is usually commonly associated with group tag, or is that just me?
I suppose it has something to do with the image that 'idols belong to the fans' or something like that, maybe?
I associate idol hentai stories always with group, forced and mindbreak because there are a lot of such stories. There are also a lot of vanilla idol stories but I must confess that "bad" stories happen to dig themselves deeper in my mind so that I could read 50 "nice" and 50 "bad" idol stories and would still think about idol stories as generally darker themed. Just take a look on all fakku stories with the idol tag and you will see that there are far less stories with idol girls having sex with multiple men than you would guess (although this is not very representative)...
Now I may get alot of down votes on this. I do hope however people are open to discussion on this topic.
I feel this idol x group trope has been done so very often and is rarely innovative. Allow me to explain
Person 1 is shy and not good with men
Person 2 really likes dicks and group sex on the dl
Person 2 invites person one to place randomly
Person 2 is messing around with a bunch of guys
Person 1 oh, um.. idk if this is for me
Random guys and Person 2 oh come on (proceed to foreplay and eventual sex)
Person 1 oh yeah I guess taking 3 dicks at once is cool
90% of this trope right there
The vast majority of hentai is not very innovative, at the end of the day it's just porn and an excuse to get some titties on your computer screen. The idol getting closer to her fans through a gangbang, the childhood friends finally overcoming their shyness, the guy getting seduced by the horny MILF next door, the wacky misunderstanding that gets two classmates boning...it's all pretty much as creative as paying the pizza guy with some pussy, we just are tricked into thinking it's something more because it's a comic book with a little reading. But it's not, the scenarios are just a little spice to stimulate your dick, not to stimulate your brain.