Three years into their marriage, the Morisawa couple longed to have a child. However, they struggled with infertility. One day, as Kana routinely cared for her bedridden father-in-law, she gazed at his senile, childlike appearance and instinctively let him suckle her breasts. Surprised by the unexpected pleasure this triggered, Kana began to feel a strange sense of "motherhood" toward him. From then on, her father-in-law's swollen body began to stir her sexual desire. Tempted by his presence, Kana impulsively guided him into her private area, giving in to overwhelming urges as she rocked her hips, consumed by a deep sense of taboo and forbidden ecstasy.