Yukino Tomioka, an adult woman with black hair, blue eyes, standing 1.57 meters tall and weighing 49 kilograms (measurements 94-53-89), is married to Tetsuo Tomioka. Following a traffic accident involving her husband and Seiji Nakamura, she and Tetsuo falsely accuse Seiji of financial liability for damage to their rare car, demanding a large sum he cannot pay. Exploiting this situation, Yukino approaches Seiji under false pretenses. She claims neglect in her marriage and proposes a sexual affair, suggesting it could reduce his debt. This proposal is part of a coordinated scheme with her husband. Their true intent is to manipulate Seiji and gain leverage over his girlfriend, Ai Fujisawa, and Ai's sister, Kokoro. After initiating the affair, Yukino and Tetsuo use it to blackmail Ai into sexual servitude, falsely presenting this as necessary to settle Seiji's debts. Yukino actively participates in entrapping both sisters. She and Tetsuo imprison Ai and Kokoro within their mansion, subjecting them to forced participation in sexual orgies designed to break their wills and transform them into mind-broken sex slaves. Yukino is present and complicit during the sisters' captivity, reinforcing the power dynamic with her husband. The scheme unravels when Seiji's brother, Koji Nakamura, seeks retribution. Koji infiltrates the mansion, subdues Tetsuo, and knocks Yukino unconscious. While she is incapacitated, Koji sexually assaults Yukino in front of her bound husband. The aftermath implies she and Tetsuo face consequences for their actions.