Kurumi is a serious and highly competent office lady working in accounting. Her long, silky hair and voluptuous big tits make her an object of admiration among her coworkers. One day, after inviting her out for drinks to celebrate her overtime work, I half-forced her into a romantic relationship. That's when I discovered her hidden side—she's a masochist who gets turned on by being dominated and scolded. From then on, under the pretext of mentoring her as a junior employee, I began training her as my sex slave, deepening our twisted bond through restraint, tickling, and humiliation, until she became nothing more than my personal cumdump and squirting plaything.