Society is abuzz with excitement over the card game Hyakunin Isshu. Amidst this craze, neighbor Yasuo visits Natsuko Kayama's home seeking her guidance in mastering the game. From that day on, Natsuko and Yasuo begin their training sessions together. However, one day, Yasuo notices that Natsuko isn't wearing any panties, leaving him shocked and flustered. Natsuko skillfully exploits his reaction, turning the tables on him. Her no-panties Hyakunin Isshu sessions grow increasingly intense, leading to bold new developments between them.