The idol is a scumbag, I agree, but Otaku is not being a scumbag here by asking her for help.
I mean, we're talking about a freaking KIDNAPPING situation, and the police/officials are too corrupt to do anything about it. Otaku is not a scumbag to ask the only person who could do something about it to help.
Like, you think it would have been better to just left the blond girl to her unsavory fate/death?