A female spy infiltrates a mansion to steal top-secret information but is captured by the mistress, who senses something suspicious. The mistress is Wakana Ai, a genuine lesbian widely known as a tickling executioner. She takes greater pleasure in watching her victims' faces twist with laughter during tickling sessions than in eating dessert, and prides herself on breaking anyone using her expert combination of tickling and lesbian domination. Inside the mansion's torture chamber, the sounds of laughter echo as the captured spy, Yuri Mizusaki, learns her fate. She is about to become part of a legitimate, historically recognized form of tickling punishment that has been practiced throughout Europe since the Middle Ages. Using her hands, fingers, tongue, and strapon, Wakana Ai subjects Yuri to intense lesbian torture designed to satisfy her own deep-seated desires. While the tickling torment may appear playful at first glance, it carries a dark historical significance as a method of punishment. Now, within these walls, Yuri's fate is sealed—how she endures it remains to be seen.