It does kind of reek of rape at the beginning, but for me personally it's always hard to tell the difference between the actual thing and just usual Japanese culture with all the "Nooo~!" 's. I mean, I could consider it not to be rape since she's technically consenting so that her misdeed isn't exposed. I dunno. I also get how coercion itself is rape. There's always a fine line with blackmail type stuff, huh?
Seriously, Mira has nailed the whole guilty pleasure thing, though. I shouldn't like this one as much as I did, but she wraps it up in such a feel good way it's hard for me to dislike it. Hell, it might be one of my new favorites of hers. But like Doctor_Hoot said, I totally get why someone would take issue with it and not like it.
I'm probably just a creepy sex pervert.