Kasumi Osawa was introduced to Otsuka, her husband Tetsu's superior at work and also his former senior from college. Tetsu had been forcibly used by Kasumi since their school days, yet still remains trapped in that humiliating relationship. One day, Otsuka rapes Kasumi. Overwhelmed by pleasure yet proud that she's doing it for her husband, she swallows his semen completely. This act becomes the beginning of Otsuka's relentless domination—ravaging Kasumi's body from morning to night, each time forcing his cum into her mouth. For both Kasumi and her husband, this marks the start of a new, twisted relationship.