"Nana, today I'm going to tie your hands and make you my obedient slave." Nana, my childhood friend, is cute, innocent, and I've always seen her like a little sister. We've always been close, and until recently, seeing Nana's panties never excited me at all—but lately, I can't suppress this overwhelming urge to dominate and ravage her completely. I want to bind her body tightly, forcing her to beg, "Master, please forgive me!" Maybe I've lost my mind... Yet, while joking around with Nana, pretending to do SM play, I suddenly found myself slipping into intense, hardcore BDSM sex for real. [A pure girl's transformation into a deeply submissive, masochistic slave.]