Umi, the sister controlled by her fuck buddy using aphrodisiacs and sex. One day, that fuck buddy finds out about her younger sister. The younger sister is pure and proud of her large breasts. As the fuck buddy tries to make contact with the younger sister, the older sister becomes suspicious but cannot resist due to her craving for aphrodisiacs. The younger sister ends up being sexually trained by her sister's fuck buddy. The sisters experience the effects of the aphrodisiacs. The man's goal is not just the younger sister but to make both sisters addicted to aphrodisiacs and sell them to a JK (junior high school) otaku. The fate of the sisters, covered in semen.
