FNS-110 - Vaginal Domination NTR. 5 days a week with boyfriend for normal sex, the remaining 2 days with boyfriend's friend for NTR portio development, resulting in a large-breasted girlfriend, Hachimitsu Rin, being cultivated into a sex-crazed psychopath.

An NTR story that began when he bragged to his best friend, "I'm having sex with my girlfriend 5 days a week." The best friend, with psychopathic tendencies, thought purely, "The remaining 2 days are a waste," and "Let's increase her sensitivity for my friend for 2 days a week." Rin was bewildered by her boyfriend's best friend's outrageous behavior, but accepted it, underwent portio development, and became addicted to an unprecedented vaginal orgasm...