The Hamasaki family is a household of three living in a certain prefecture, where the father's company struggles amid economic downturn. Mao Hamasaki has stepped up as the bright and cheerful pillar of the family, filling the void left by her deceased mother. However, this family harbors a deeply twisted dynamic—the father has taught his daughter various sexual acts, and Mao eagerly enjoys them. Raised in this abnormal environment, Mao willingly offers her body for the sake of her family, supporting them with the fragile strength of a Heisei-era girl. This is a story of familial devotion intertwined with hidden erotic warmth woven into everyday life.