After losing his job and returning to his parents' home, Tetsuo is abandoned by his family and sinks into despair. The only one who supports him is his younger brother's wife, Mao. However, as Tetsuo's job search continues to fail, he can no longer resist the sight of Mao's glistening skin and impulsively takes her. Coming to his senses afterward, Tetsuo resolves to leave the house and apologizes to Mao. To his surprise, her response is unexpected. Amid the humid heat of a tropical night, the sweat-soaked brother-in-law and Mao, driven by desire, begin forging a new relationship.