Due to his wife's hospitalization, the husband is forced to live alone—until his daughter-in-law's mother arrives from their hometown of Kobe to Tokyo. This long-awaited reunion marks the beginning of a new life together under one roof, with the stepmother and son-in-law sharing intimate moments. The stepmother boasts a voluptuous, shapely ass, and as their private time increases, he finds himself helplessly drawn to her lewd charm. With his wife away, their relationship deepens, spiraling into days filled with raw desire. Living in close quarters, the son-in-law becomes completely captivated by her irresistible allure.