Chisato and Fumiko are alone on a hot spring trip. Her husband doesn't find out, but the two are lovers. Chisato boldly proposes, ``Let's go for a walk in a yukata without underwear,'' because of her sense of liberation away from her daily life. The two who tasted the thrill of throbbing further devour each other's erogenous zones in the open-air bath. The sense of immorality that "someone might come ..." enhances the pleasure of the two people more than usual, and the two who can not stand it are immersed in more radical play with the obscene tools they prepared ....
