Interesting fact: most idols are [url=http://nextshark.com/japanese-idol-singer-sued-for-dating-fan/]contractually prohibited[/url] from having any romantic relations (for the sake of keeping their "purity" and "integrity" intact), lest they be publicly shamed and their career wrecked.

The best way to extort, then, is to threaten an exposure of a relationship, whether real, staged (by having a male villain seduce her), or fake (but convincing).