Rin was married off due to her parents' strong wishes, only to find herself entering the powerful Toma Zaibatsu, where a woman reigned supreme. Under the authority of matriarch Toma Sachiko, her husband was placed under the control of his older sister, Yuki, losing even basic rights within his own household. Rin was shocked by this bizarre family structure—until one day, by Sachiko's orders, her husband was suddenly sent overseas. From that moment on, Rin begins to uncover the true nature of her marriage, the Toma family's inherited sexual deviance, and Yuki's nearly insatiable lustful desires...!