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 must keep hidden. I want to do S&M. I secretly buy tools for my personal use - stare at it, touch it. And then one day as I was expelling myself of my urges, I noticed that someone had entered my room and saw the secret. Let's try setting a trap... I turn to see who discovered my secret. And so, our abnormal relationship began.