Sarina is a housewife living in a housing complex, troubled by her sex life with a husband who lacks both stamina and libido. Kishikawa, a middle-aged man who just moved in next door, decides to recommend a tonic produced by the pharmaceutical company where he works. A few days later, while visiting Sarina's home, he happens to peek through an open window and catches her in a lewd state, masturbating with her hands roaming over her sweaty skin. The two, who were never meant to cross paths, use this moment as a catalyst to begin a passionate affair, engaging in sex so intense they both end up drenched in sweat...
