as for the whole extortion thing....fujiwara broke a vase, asked miu to keep it a secret, who clearly says in thought she wouldn't tell anyways, then states "i'll do anything!" so when miu asks her to go out with her, she agrees. She's the one who said she'd do anything, without a threat being placed on her for it. then later after the whole karaoke thing, clearly states the convenience for her to finally have it publicly out that they were "dating." yes, she didn't know miu wouldn't tell, and yes, japanese people are very subservient and have a difficult time saying no, but i can hardly look at the whole thing as "extortion." it would be if miu blatantly says, pretend to go out with me or i'll tell, without the offer to do anything she is asked to do already out there on the table. if anything, it's actually the other way around. i mean, miu is using fujiwara to see what it's like to date someone, which naturally will grow, however platonic, feelings towards each other.
Miu said "just kidding, I don't mean it, sorry, you don't have to!" and almost fell over out of embarrassment.
And Fujiwara said okay, let's do it! anyway. I think that's the end of the extortion concern.