Riko and I have lived close to each other since we were kids, and our parents are good friends. We grew up together, so I never saw her as a woman, just as a male friend. But one day, I happened to see the cleavage of Riko's big breasts, and for the first time I thought of her as a woman. I never thought that such a defenseless big-breasted girl was so close to me... Once I realized that, I couldn't stay still. I can't wait to have sex with my childhood friend! Please, Riko! Let me do it!