I don't think that Yayoi was raped ( a REALLY close friend of her perhaps), she work with a lot of guys and doesn't seem bothered about it. Don't wanna think this way,but maybe she is just fooling around with Shion, i mean these people spent most of the time in that building, there is to have something to make them relax. Really wanna believe and to be on the side of yuri haha
Yayoi is way out of kougami's league