Scientist Jun was a deranged mad scientist obsessed with implanting male genitalia into soft-bodied women to achieve the ultimate physical perfection. His first experimental subject was Azusa, dubbed "Futanari Unit One." As Jun predicted, the beautiful girl now equipped with a massive cock became the perfect lesbian partner to satisfy his own desires. But Jun's lust knew no limits, and his next target was Nanako, whose provocative, jiggling, extra large breasts swayed with every step. After kidnapping her and successfully transforming her into a futanari, Jun indulged himself in endless pleasure. However, Nanako had yet to realize that, after enduring intense training, her suppressed sexuality would soon erupt uncontrollably...