An angry sister

Kuroki Kazuhiko, who works as a game planner, won a prize in a Famicon game. With that win, he had enough money to join the BD Photography研究会. “BD” stands for bondage and sexual stimulation. In other words, it’s a club where members can engage in SM-related activities. Kazuhiko realized his own interests. He started to want to bondage women. One day, Yuki, his sister-in-law, who married a doctor two years ago due to her parents’ remarriage, visited Kazuhiko’s room. Yuki didn’t get along with her husband, so she ran away from home.