Five years ago, Tsubomi and Rei's mother remarried. Both of them have a more prosperous life than before. However, due to the hardship of raising two children, their mother's health deteriorated, leading to frequent hospitalizations. Now, their stepfather is left alone to care for the two daughters. But it seems that both of them are indifferent to their stepfather. They do not listen to him, do not greet him, and completely ignore him. Frustrated by Tsubomi's disrespectful attitude and the lack of intimacy, the stepfather decides to punish the two daughters for not appreciating his care all these years by... making them his sex slaves.