I think I know where you are talking about- On the Meji Dori side of Akihabara Station, behind Yodobashi Camera, there is a multi-floor building with various amusements. A few themed massage shops that may or may not be rub and tug, etc. The pink salon changed into a maid ear cleaning shop (yeah...I know), and after that, I think it shut down and turned into something else. As recently as a few months ago, the sign was still on the street, but turned backwards.