Based on the erotic game by Noesis. A kind and reliable older sister, Mizushiro Ayaka. A younger childhood friend and now my girlfriend, Tsurutani Ayaka. While I'm happily getting along with the two, I wasn't satisfied. That is because I have a hobby that I cannot let surface. I want to do, S&M. I sneakily buy tools for my personal use, stare at them, touch them. One day as I was expelling myself of my urges, I noticed that someone had entered my room, and closed on to that secret. "Let's try setting a trap" I expose who discovered that secret. And so, our abnormal relationship began. (Source: Noesis Homepage)