Kotono, the honor student who looks good with twin tails, lives almost alone as her father is always busy with work. However, behind her honor student facade, she harbored a masochistic desire to be irrumated and ejaculated inside. One day, while indulging in self-pleasure, she was caught by Nakata, the plumber, who then blackmailed her into sexual acts. Since then, she became Nakata's sex slave, subjected to lewd acts...
