Aki diligently cares for her stepfather without complaint, treating him with the same warmth and affection as a real daughter would. Her kindness fills each day with meaning. But one day, her stepfather drops a bombshell: "This summer, I intend to take my daughter-in-law." These words shock Aki to her core. The older man, embodying the rough demeanor of a Showa-era patriarch, harbors intense desire for her—transgressing the taboo of his son's wife, captivated by her softness. Though confined to his sickbed, those words reignite his dormant heart, unleashing a storm of overwhelming lust.