FNS-110 Deep Vaginal Domination NTR: Five days a week of normal sex with her boyfriend, the other two days the large-breasted girlfriend's body is developed by her boyfriend's friend, and she was raised by a psychopath obsessed with sex. —Rin Yamitsu

This is an NTR story that begins with Rin bragging to his best friend, "I have sex with my girlfriend five days a week." His best friend, a psychopath, believes the remaining two days of the week are a complete waste and should be used to enhance her sensitivity. Rin is confused by his friend's crazy behavior, but he accepts it, and as his libido rises, he becomes addicted to vaginal orgasms he's never experienced before…