One day, Kurumi's husband's friend came over to visit. As the two drank and became intoxicated, they began chatting excitedly about adult entertainment. Kurumi, who had been living an ordinary life, gradually grew curious about the conversation. While her husband slept, she accepted money from the friend and ended up having sex with him. That experience became a turning point, drawing her deeper into a secret relationship with him, until she was completely consumed by their illicit affair.