Born into a prestigious family, Ryouko, and Ayano, who worked as a servant in Ryouko's household. Ryouko's late father was kind-hearted and had generously arranged a proper funeral for Ayano's mother, becoming her benefactor. Out of gratitude, Ayano endured Ryouko's cruel and sexually abusive treatment for years. However, fate soon shifts in Ayano's favor. After winning a massive lottery prize, Ayano begins orchestrating the downfall of the company Ryouko inherited, quickly bankrupting the sheltered Ryouko. At last, the master-servant dynamic is reversed. As their power balance shifts, their relationship takes an intense and transformative turn.