It was winter 5 years ago when I was unfaithful. At that time, I found out that her husband was having an affair and I was in an indescribable loneliness. Knowing or unknowingly of my heartbreak, Sho-kun, who is a friend of her son, confessed to me. Even though I know it's unforgivable, every time a boy who is older than me asks for my body, my sense of guilt is drowned out by the blue and strong pleasure... As she spends her days making excuses like, ``I'm going to play with fire just once,'' her feelings for him grow.