Ruka and I have been childhood friends for so long that she feels almost like family, yet lately I cannot stop imagining how badly I want to break her. Inspired by porn, I impulsively ask if she wants to try BDSM role-play. Though hesitant, she agrees, and we become master and slave. What begins as a casual experiment goes much further than either of us expected: Ruka awakens as a devoted masochist, shamelessly thrusting her hips and begging for more training.