Rika, who loves reading, has recently become obsessed with the history of medieval torture and spends her days immersed in books. After school, she always reads at the same park. One day, while deeply engrossed in her book, her consciousness begins to waver, drifting away from reality. When she awakens, her limbs are bound by heavy iron shackles, rendering her unable to move freely. A man dressed in black appears and begins to manifest the dark fantasies and desires buried deep within Rika's mind. Initially trembling with fear and shame, Rika gradually succumbs to the men's training, losing herself completely as she begins craving pleasure. Through this process, she delves deep into her inner self and discovers a new side of her identity.