Mitsuo, a good-for-nothing brother-in-law who is on leave from work, is shunned by his family and the midsummer heat is making him feel pent up. Mitsuo's frustrations are directed at his younger brother's beautiful wife, Kana. While his talented younger brother is away on a business trip, Mitsuo finally rapes Kana. In the scorching heat, Kana is covered in sweat and her desires explode, and she can't resist Mitsuo's assault. When her husband returns home, Mitsuo rapes Kana as if this will be the last time.