Yuriko grows increasingly frustrated with her husband's inadequacy, her daily sexual dissatisfaction building until she can no longer endure it. One morning, she notices her son's morning erection upon waking, deepening her inner turmoil. As these moments accumulate, she loses her rationality and begins seducing her own son. It doesn't take long before they cross the forbidden line. As the mother and son's incestuous relationship intensifies, a secret plan between father and son slowly begins to unfold. Ultimately, these dark threads lead to a shocking upheaval that tears apart the very fabric of their family bond.