The wife's best friend Rin is troubled after being asked for advice about her husband's persistent cheating habits. No matter how much she tries to reason with him, he only makes excuses, leaving her helpless. Eventually, Rin decides to investigate the root cause of his infidelity. To her shock, she discovers an unbelievable reason—he claims women are irresistibly drawn to him because of his large penis and superior sexual skills. Unwilling to accept this, Rin begins seeking new excitement in her own life. That's when she notices his impressively large cock. The sight alone triggers an involuntary physical response from her body...