The frail female student, Yura, wouldn't resist being touched on the nipples; instead, her sensitivity would gradually increase. (Yura Kano SSIS-949)

Normally a shy and reserved female student, she never expected to have such sexy nipples. They would become erect with just a light touch. This abnormal sensitivity could only be pushed to its extreme by developing it into a sexual fetish... Slowly pinching, sucking, and rubbing them, adding new pleasures, using oils and toys to make her nipples look like cheese, and violently pounding them with a huge penis while applying pressure, completely plunging her into the abyss, making her no longer satisfied with ordinary sex, and turning her into a cute little sister with premature ejaculation and perverted behavior.