Ema Ichikawa, who should have grown up by now, climbs onto her uncle's lap just like when she was little, teasing him with her irresistibly sweet behavior. When he lightly touches her sensitive nipples, she reacts instantly, driving him wild with excitement. Even in front of family, she secretly gets her nipples played with, desperately trying to suppress her arousal—making her all the more erotic. From that day on, nipple stimulation becomes their daily game. Using vibrating nipple suckers, nipple irrumation, and forced nipple masturbation, they explore every method imaginable. Gradually, her nipples grow hypersensitive, until she's fully conditioned to take her uncle's massive cock deep into her mouth.