Kazuhiko's father remarried a year ago and introduced his new stepmother, Misako. She was beautiful and captivating to him, but as time passed, his father became distant from her physical and sexual needs. Meanwhile, Misako received lewd phone calls and gifts from an anonymous caller. As she couldn't resist the temptation any longer, she realized that the caller was none other than Kazuhiko, her stepson. She began to fall deeply in love with him but also felt guilty for cheating on her husband.
In Volume 1, Semishigure, Otouto., Naburu Musume-tachi, and Nureiro no Sasayaki, we see Kazuhiko's growing attraction towards Misako and his attempts to keep their relationship a secret from Yosuke. However, as they become more involved, Emiko, Misako's younger sister, also catches Kazuhiko's eye.
In Volume 2, Natsu-iro and Adegoromo, we see how Misako struggles with her guilt and the consequences of cheating on Yosuke. She tries to keep their affair a secret but finds it increasingly difficult as she becomes more deeply involved with Kazuhiko. Meanwhile, Emiko also develops feelings for him, adding another layer of complexity to the situation.
Overall, this story explores themes of love, betrayal, and family dynamics in a captivating and thought-provoking way.