Hikari and Noa are mom friends living in a luxury apartment, married to famous people. The two have very strong libidos and only talked about their frustrations. In the midst of that, they learned about a secret party. It's a membership-based event where only the rich gather, and because they wear masks, their faces won't be revealed. So they decided to participate, and a bizarre scene unfolded. The world of SM that they had never seen before, and the greatest masochistic pleasure they had ever felt. They come to know that various sexual acts in a bound state are the most pleasurable... The two's new doors have just opened now.