While receiving daily updates from his wife who had returned to her hometown, Akio quietly cherished the joy of soon becoming a father. However, contrary to his desire to welcome her back in a perfectly clean home, the house gradually fell into disarray. Amidst this, his wife's older sister, Chinatsu Mikami, came to visit and offered to help with the housework. Relieved to have everything in Chinatsu's capable hands, Akio began unconsciously noticing her cleavage and hips as she worked. Becoming aware of his own growing attraction, he found himself increasingly drawn to Chinatsu—despite knowing she was his sister-in-law—her caring presence blurring the lines of familial boundaries.