Married woman Ayane Suzukawa once worked as a swimming instructor, but her life took a sudden turn when her self-employed parents fled after accumulating massive debt. As their joint guarantor, Ayane was left responsible for the entire debt. Trapped in desperation and hiding it from her husband, she begins a secret life of submission and training. Bound tightly in a competitive swimsuit with ropes digging into her skin, her deep masochistic nature emerges as she fully transforms into a sex slave. Sacrificing herself repeatedly, she continues to serve without end. Ayane's life becomes an endless cycle of misfortune and domination.