It was three years ago that Kyosuke, the son, left home to go to college in Tokyo, and two years ago that his father quit farming and went to Sendai to work, and remarried his wife, Natsumi. The stepmother and son only saw each other twice a year, during Obon and New Year's. And this summer, mother and son returned to their hometown and reunited for the first time in a long time, to their wooden house without air conditioning... This year has been extremely hot, more than usual, and the obscene sweat that covers Natsumi's whole body is driving Kyosuke crazy, and he begins to think of Natsumi as a woman, not just his mother...