The Moritaka household became a home of men only after the stepmother left. When the second son and his wife Kasumi began living together, their relationship started to grow slightly awkward. One day, Kasumi noticed her father-in-law giving her uncomfortable stares, unsettling her emotions. Busy with housework, she was suddenly assaulted by her father-in-law, her lower body groped and teased. Though she resists, his persistent advances and his surprisingly powerful cock—unimaginable for his age—deliver pleasures unlike anything she's experienced with her husband. After sending her husband out, she gets caught by the eldest son, leading to an even deeper entanglement. The family's balance begins to collapse as the forbidden relationships escalate.