One day, my childhood friend Ami suddenly announced she was getting married. Facing the harsh reality that as a virgin, I had no chance with her, she gently suggested, "Then... how about practicing with me?" Ami, who'd always been kind and affectionate, unexpectedly proposed sex practice. Hesitantly, the training began. But when it came to actual penetration, moral concerns held me back—so we could only rub through our underwear. Yet something started seeping from her panties. Then, even through the fabric, my dick ended up penetrating her pussy. By now you understand—this is sex. With just 1mm of fabric between them, forbidden excitement and eroticism explode. Overcoming reason, the two finally unite completely. This secret sexual training evolves into an uncontrollable impulse.