Yukiko, the older sister, finds herself drawn to her nephew's erect cock when he's left alone at home, her groin heating up with desire. Losing all sense of reason, she indulges in creampie sex with him. At night, she greedily sucks off the newspaper delivery man, swallowing his load after intense blowjob. Memories of the daytime encounter haunt her mind, driving her to seduce her nephew again, climaxing in another forbidden creampie. It was a blissful moment of ultimate satisfaction, fulfilling both her body and soul.