Submissive wife Satsuki is forced to work as a hot spring companion at a rundown resort to pay off her husband's FX trading debt. In front of her husband's eyes, she is subjected to sexual acts by the inn's owner under the guise of "training," enduring deep humiliation. As she serves various guests, Satsuki gradually hones her skills, mastering the art of sensual bathing over time. This transformation brings profound changes to her inner self as well.