In the hush of their shared home, Nezuko's gaze lingers on her brother Tanjiro, her heart pounding with a sinful desire. She watches him train, his body honed and strong, her imagination running wild with fantasies of his touch. Tanjiro, unaware of his sister's lewd thoughts, continues his rigorous routine, his sweat glistening under the dim light. One evening, Nezuko, driven by her unquenchable thirst for her brother, decides to act on her taboo urges.