FNS-110 Deeply Possessive NTR: She has normal sex with her boyfriend five days a week, and on the remaining two days she is trained by her boyfriend’s friend, turning into a highly lustful, voluptuous girlfriend, Rin Yamitsu

A NTR story that began when he bragged to his best friend that he was intimate with his girlfriend five times a week. His best friend, who had a psychopathic streak, genuinely thought that the remaining two days a week were a waste and that he should help improve his girlfriend’s sensitivity for his friend’s sake. Confused by her boyfriend’s best friend’s bizarre behavior, Rin gradually accepted it, underwent intimate training, and became hooked on a new kind of pleasure she had never experienced before.