What was meant to be a simple visit turns into an instant plunge into a whirlpool of forbidden lust. Kusuo visits the hot spring inn of his childhood friend Kaede, and amid the rising steam, a gentle young mother, a cold and aloof city woman, and a sharp-tongued yet soft-bodied best friend appear one after another. Slick skin presses close, and temptation and conflict keep heating up in the scalding water. Layer after layer of defenses is torn apart, and desire bursts forth. By the end of this night, everyone is thoroughly pierced through, and their relationships can never return to the way they were.