〇Kotone Tsuki currently works as a dentist. She boasts of being a sex enthusiast, and like a doctor studying the structure and form of the human body, she continues to pursue research and analysis of pleasure. She can't get enough of having sex while watching men's voices and expressions, and she can already be called a lewd woman. Once inside a hotel room, she passionately engages with a man, as if showcasing the results of her sexual research. Meanwhile, 〇Nakasaki Yukine is a woman trying to conceive whom she met this time. Since getting married, she has wanted a child and has been having sex frequently, but she hasn't been blessed with one. As a result, the act has become routine, and she's troubled by the lack of stimulation and excitement. Then one day, during a lunch with an old female friend, the conversation got heated about playing around with men, and she learned that everyone was having more fun than she imagined. Inspired by this, she became interested in playing with fire herself.