Yui is a married woman with a diligent businessman husband. Her brother is unemployed and is looking for a job while living at home with his parents. While his brother-in-law is spending his time at home with his happy younger brother and his wife, he finds Yui's body extremely dazzling. On a sweltering tropical night, the sight of Yui sleeping with her sweaty chest exposed makes the brother-in-law's desire overflow with the sweat...