Kurusu Saki's beloved Akizuki Kaya has disappeared. She was furious, but was shocked to find out that her father was involved in the development of Yagami's sex device. Cruelly, she was given the sex device her father had developed, and it brought out her incredible feminine instincts that had been hidden until then. Kokoro of justice that wants to fight against criminals and her sad desire to know the truth about her father become intertwined. She is consumed by the dark side that lurks within humans.