The scorching heat continues relentlessly, and life would be so much easier if they had an air conditioner. But the Kobayashi family, living modestly, doesn't own one. Watching his mother tirelessly working every day—cooking, doing laundry, and rushing off to her job—the son wishes he could provide her with a cool, comfortable space. Yet this kind, caring son gradually finds himself overwhelmed by intense arousal at the sight of his mother's sweaty body and damp clothing, without even realizing how deeply he's affected.