The summer days that pass, the countryside scenery that disappears, and the long and short three years of being a high school girl. Tochigi, a land surrounded by mountains and rivers. The energetic summer that passed in the blink of an eye. The original countryside scenery that is being lost year by year due to urban development. The sensitive youth is rushed by. However, it is precisely because of this place that she is nostalgic and realizes that she is a masochist, and wonders what to do. Not knowing whether it is a good thing or a bad thing, she enjoys lazy sex. What does the ray of light that occurred in her last summer that she cannot tell anyone about mean to her? Only her anus, which remains wide open, knows the answer.