Kanna, a sales manager at a Tokyo office-equipment company, is crushed by excessive expectations, punishing hours, and distance from her husband. She is also frustrated with her incompetent subordinate Yoshino, until one careless moment allows him to pin her down and recognize her hidden masochism. From then on, he takes her to an SM hotel during lunch breaks, carving pain and pleasure into her body until the beautiful boss is trained into his obedient, abused dog.