The protagonist of the hentai Mamiya Yuichi is an unremarkable young man, but now he has not the most pleasant changes in his life. He has to move to live in his father's house, who has a new wife and two grown-up daughters. Soon his father leaves on a business trip abroad, leaving Yuichi alone with his new family. It is time to execute a plan of revenge and he buys a pointer capable of hypnotizing whoever it hits. The first person he decides to test the gadget on is the mother of the Mifuyu family, and then her daughters Akiha and Natsuki...