Hibiki is the principal of Otsuki Academy, her daughter Iori and her close friend Yu also work here. In addition, there is Kiyoshi, her stepson from her husband's previous marriage. Before his death, her husband asked her to take good care of Kiyoshi, so she always indulges him, allowing him to work on cleaning and repairing miscellaneous items for the school. But Kiyoshi has a twisted hobby, which is stealing women's underwear! He steals from students to teachers, even his stepmother! Iori knows about this and has told Hibiki many times, but she still can't bring herself to fire Kiyoshi. However, because Kiyoshi's behavior becomes more outrageous, Hibiki asks Yu to find evidence of his underwear theft. When Yu goes to Kiyoshi's room, she discovers him in the act with the stolen underwear.SDDE-625 Unlocking the seal for evil spirits, the young man gained the power to control others' minds While Yu is scolding him, a voice suddenly speaks out. It seems that only Kiyoshi can hear this voice. The voice entices him to remove the seal under the cabinet, and after removing it, he will be given the power of a demon and can control everything within the boundary. Kiyoshi follows the instructions and removes the seal. From then on, he has the power to manipulate the minds of others, and the first thing he thinks of is having sex with the beautiful nurse Shinoda that he has always desired, followed by his stepmother and alluring step-sister...
